Congenital defects and minor developmental anomalies. Deformities. Minor developmental anomalies, the meaning of anomalies in genetically determined disorders of growth and development in children
CHAPTER 23 CONGENAL DEFECTS AND MINOR DEVELOPMENTAL ANOMALIES
CHAPTER 23 CONGENAL DEFECTS AND MINOR DEVELOPMENTAL ANOMALIES
Historical information
In clinical genetics, teratology (dysmorphology) is identified as an independent scientific direction, studying the etiology, pathogenesis, clinical manifestations, methods of diagnosis, treatment and prevention of congenital major and minor developmental anomalies.
VPRs have been known since ancient times. This is evidenced by cave paintings of conjoined twins made many millennia ago (Australia), an image of a patient with achondroplasia (Egypt), the fact of congenital clubfoot among Egyptian pharaohs and other examples. One of the first publications devoted to the description of VPR is a book published in 1616 in Padua. Intensive development of teratology occurred in the 19th century. First of all, this applies to the works of J. Meckel, who described the morphology and created the first anatomical classification VPR. Subsequently, the works of father and son E.Zh. were published. Saint-Hilaire and I.E. Saint-Hilaire, which applied experimental method to study the causes of VPR (impact of mechanical factors on chicken eggs).
In Russia, the beginning of teratology was laid by the Decree of Peter I of February 13, 1718 on the creation of a museum of ugliness in St. Petersburg (in the Kunstkamera), where embryologists K.F. worked with museum exhibits. Wolf and K.M. Bare. The first Russian work on teratology was “Review of various human deformities” (Zagorsky P.A., 1811). In 1847, the first monograph by P. Dubovitsky, “A Look at Ugliness in General,” was published, where teratological concepts and classifications were given, the etiology and mechanisms of the pathogenesis of defects were considered.
However, the intensive development of domestic teratology began at the beginning of the 20th century. after the rediscovery of the laws of heredity in 1900. Among the most famous works on this topic It should be noted the works of I.V. Davydovsky, A.P. Dybana, P.G. Svetlova, S.D. Shakhov and other morphologists.
Qualitatively new stage the development of Russian teratology was associated with the works of E.F. Davidenkova, G.I. Lazyuka, A.A. Prokofieva Belgovskaya, V.P. Efroimson, one of the first to use methods of medical genetics in the study of developmental defects. And finally, modern stage The development of teratology, which began in the mid-80s of the last century, is associated with deciphering the causes and mechanisms of congenital diseases as a form of human hereditary pathology.
general characteristics
Doctors of any specialty constantly encounter congenital malformations in children and adults. In some cases, this pathology is easily detected even at the first examination of a newborn (anencephaly, microcephaly, hydrocephalus, cleft lip and palate, shortened limbs, cranial and spinal hernias, etc.). In other cases, congenital malformations are detected only when using a syndromological approach and clinical and instrumental examination methods (heart defects, kidney defects, respiratory organs, digestive diseases, etc.).
As a rule, congenital pathology has a significant impact on a person’s health. However, there are known birth defects that do not have such an effect. According to WHO, the population frequency birth defects and developmental anomalies among the population is 1.5-5% (in some countries - from 2.7 to 16.3%); average frequency- 3%, or 30 cases of congenital birth defects per 1000 births. In the postnatal period, the number of children with defects reaches 6% by the age of two and 8% by the age of five. In structure total mortality children with congenital malformations account for up to 15-20%, and perinatal mortality - from 4-7.7 to 26-29% (according to prosektura data).
Congenital pathology is extremely diverse, the number of defects and developmental anomalies is in the hundreds. They are detected in all systems of the body: both single bipolar and macular disorders, and entire complexes of multiple developmental defects. Among them, in first place in terms of frequency of occurrence are isolated malformations(identified in one system of the body). At the same time, neural tube defects are more common than others - 8.4-22.3% (central nervous system defects account for over 30% of such defects). This is followed by heart defects - 10.9-21.0%, limb defects - 7.4-24.5%, genital defects - 2.4-7.5%.
Developmental defects that are simultaneously detected in two or more body systems are called multiple defects. Their frequency is 7.9-18.2%.
Differences in the incidence of congenital defects have regional characteristics and depend on the completeness of the recording, the clarity of the concept (what is classified as congenital malformation), the numerical, national and age composition of the population, historical, ethnic and demographic factors, geographical and environmental conditions, as well as on the duration of observation. specific region.
To study the concepts, describe and account for BAR and MAR, special methodological developments and teaching aids: dictionaries of terms, standardized methods for examining patients with congenital pathology, based on clinical, morphological, anthropometric and other characteristics (see Chapter 17).
BAD stands for persistent morphofunctional disorder (see Chapter 3). The following concepts are used as synonyms for bipolar disorder: congenital defect, developmental defect.
Typically, bipolar disorder refers to defects that arose in utero as a result of a violation of embryogenesis or (much less often) as a result of a violation of fetogenesis, and very rarely - developed due to a violation of the postnatal formation (maturation) of organs, which is a manifestation of endocrine disorders (for example, pituitary dwarfism, gigantism and acromegaly).
At the same time, postnatal disturbances in the proportions or sizes of organs should not be classified as bipolar disorder. Also, one should not call bipolar disorder a deformity or ugliness, because the term “ugliness” is rather of a social nature (social freak, “degenerate” of society: bandit, killer, criminal, criminal). Obviously, this term should not be used in medicine, where it would be correct to use the term “sick person” instead.
In turn, MAR (its many synonyms - dysembryogenetic trait, stigma, dysgenesis, dysmorphological trait, dysplastic stigma, microdegenerative trait, microtrait, etc.), although they belong to persistent morphological, or rather to more subtle histological changes, do not appear beyond the boundaries of the norm and are not accompanied by functional disorders. That's why medical significance MAP is less pronounced than the BAR value.
Principles of classifications
There are several known classifications of BAR, which are based on different principles.
In particular, defects differ in the sequence of occurrence in the body (primary and secondary defects), time of exposure to the teratogenic factor that caused them, localization and other parameters, which seriously complicates their diagnosis.
Table 13 shows the classification of defects according to etiological principle, indicating their types and frequency.
Table 13. Classes, types and frequency of bipolar disorder depending on the cause (%)
As follows from the data in this table, there are two classes of BD (isolated and multiple), each of which has 6 subclasses:
Genes inherited in autosomal recessive and autosomal dominant types (two subclasses);
Multifactorial additive defects (genes + environmental factors);
Defects in chromosomal syndromes (gene and chromosomal imbalance);
Defects of exogenous origin (environmental factors);
Defects of unknown origin (not attributed to any of the known types).
Foreign dysmorphologists distinguish four types of clinically significant birth defects development.
First type- this is actually a developmental defect (“malformation”) or a morphological defect of an organ (large area of the body), resulting from developmental disorders under the influence of internal reasons. This implies that the organ rudiment is initially abnormal,
and its development cannot follow a normal path. This type of defects, for example, includes defects caused by chromosomal syndromes (polydactyly) and defects caused by gene mutations (Meckel syndrome).
Second type- is a disruption or morphological defect of one organ (large area of the body), resulting from the influence of external factors on the original normal process development.
Disruption is a synonym for a secondary defect, therefore, in the postnatal period of an individual’s development it can be extremely difficult to determine: is the defect identified in him a primary defect or is it disruption?
For example, aplasia radius in Holt-Oram syndrome it is a defect, and in thalidomide syndrome it is corruption.
Third type- this is a deformation or abnormal shape, size, position of a body part as a result of the influence of external mechanical forces (non-destructive) or internal forces on the fetus. In this case, external forces can lead to mechanical compression (for example, the urethra), reduction in size and deformation (for example, the uterus), as well as defects in the nervous, muscular and (or) connective tissue fetus Internal forces can cause fetal hypodynamia, which, in turn, will lead to arthrogryposis, unusual position of the limbs or parts of the fetal body, reduction in the size of the limbs, pterygium, lack of formation of flexion folds and other types of deformities up to congenital kyphosis (kyphoscoliosis).
Deformities can also occur in the postnatal period, for example, asymmetry of the skull in children with congenital hypotonia, for a long time lying in one position.
Other examples include amniotic bands ( fibrous cords) between the fetus and the amnion, leading to specific syndrome, called the ADAM complex.
Fourth type is dysplasia or abnormal organization of cells in the structure of tissues. Numerous examples of dysplasia are known: ectodermal dysplasia, Marfan syndrome, osteogenesis imperfecta, Ehlers-Danlos syndrome, etc.
It should be noted that both abroad and in Russia, to explain (express) the etiological and pathogenetic connections between different types developmental anomalies, the following concepts were proposed: consequence, syndrome and association.
Consequence- this is a type of multiple anomalies that arise as a result of one known or suspected anomaly or as a result of the action of a mechanical factor. So, the main vice is spina bifida- can lead to the following consequences: paralysis of the lower limbs, muscle atrophy, clubfoot, urinary tract infections, kidney damage, constipation and intestinal dilatation.
An example of a consequence caused by a mechanical factor may be the above-mentioned arthrogryposis, the pathogenesis of which is associated with fetal physical inactivity, which, in turn, can be caused by various reasons (myopathy, neuropathy, central nervous system damage, oligohydramnios).
Another example of a consequence is the sporadic anomaly of Pierre Robin, in which the primary defect is microgenia, and its consequence will be other defects and symptoms of the disease: glossoptosis, reduction of the oral cavity, preventing the closure of the palatine plates (resulting in cleft palate).
The next example is Potter syndrome, in which oligohydramnios is pathogenetic mechanism, and etiological factors are due to genetic causes (autosomal recessive polycystic kidney disease) or mechanical causes (compression of the ureter). The result is renal agenesis.
It is important to emphasize that in all cases of investigation, a single triggering pathogenetic mechanism is observed.
Syndrome denotes a stable combination of two or more developmental defects detected in different body systems. In connection with this concept, we should recall another concept similar in name “ clinical syndrome"(most severe symptoms separate disease or their groups, as well as individual periods of the disease), significantly different from the concept of “teratological syndrome”.
As is known, the basis of teratological syndrome is always one reason, which may be gene mutation, chromosomal aberration or teratogen.
On the other hand, if we are talking about developmental defects that are not related to each other (etiologically and pathogenetically), then another concept is used - association, having a completely different meaning in comparison with a similar concept when
multifactorial pathology, where it reflects the most high frequency a polymorphic marker gene for a certain MD (see Chapter 22).
As a teratology concept, association denotes a non-random combination of several developmental anomalies in two or more individuals, but not a consequence or a syndrome.
The practical significance of this concept is that the presence of one developmental anomaly included in the teratological association should alert the doctor in terms of searching for other developmental anomalies that are also included in it. For example, detection of thumb hypoplasia in a newborn suggests the need to be examined for signs of VATERL association.
In teratology, with all the variety of consequences, syndromes and associations, few types of congenital malformations are known, included in different complexes of defects.
At the same time, the same malformation can be isolated, primary or secondary, and can be part of a symptom complex of a monogenic disease, teratological or chromosomal syndrome.
Differential diagnostic value of minor developmental anomalies
For registration and accounting of IDA back in the 20th century. a standardized methodology was proposed, according to which MAP can be divided into three groups: alternative, measurement and descriptive.
Alternative group- these are MARs, which (like gross defects) are either present or not (papillomas, notches, alopecia, scalp defects, etc.).
Measuring group- these are MARs, determined by an absolute or relative quantitative value (lengthening, shortening, decreasing, increasing, displacement of a part of the body or organ, change in surface curvature, etc.). In this case, based on statistical laws, only MARs whose deviation from the arithmetic mean does not fall within 2 sigma should be taken into account.
Descriptive group- these are MARs for which it is difficult to apply quantitative methods of study (for example, changes in the shape of soft tissues, hair color, skin, etc.). In this case
their assessment in points is acceptable: I point - weakly expressed MAR, II point - clearly defined MAR, III point - pronounced MAR (with extreme values).
It should be noted that the attention of teratologists has always been drawn to the differential diagnostic value of MAR when characterizing not only congenital, but also hereditary pathology. Most MADs are characterized by stability, which is noted already in the neonatal period and does not disappear with the age of the child.
For some MARs, on the contrary, they are characterized by their change (up to disappearance) as the child’s body grows and develops, i.e. age dynamics. These, for example, include such signs as capillary hemangiomas of the neck and lumbar region, high palate, saddle shape nose, hypoplasia of the big toe, moderate skin syndactyly of the II and III toes.
Age-related dynamics were also noted in the epicanth, cleft uvula, sandal-shaped cleft, low-lying ears, and skin pigmentation.
Differences in the characteristics of MAP in full-term and premature infants are highlighted. There was a positive correlation of some MAPs with the length of the child's gestational age.
The dependence of the characteristics of a number of MAPs on the nationality of the patient has been established (protruding upper lip, width of the mouth, shape of the nose, epicanthus, etc.). For example, epicanthus is found in 60-65% of men living in Asian countries, 57% of Volga Tatars, 25% of Kazakhs; rare in Australia, India and Indonesia; practically never found among Russians.
Another example is the narrow palpebral fissure characteristic of the Mongolian race.
Complexes of 4, 5 MAP or more can be considered as markers of a number of hereditary diseases and syndromes of multiple congenital malformations, i.e. taken into account amount of MAP. For example, polydactyly, hypertelorism of the eyes and nipples, extra nipples - these MARs suggest the presence of defects in the patient urinary system.
The following example is a cleft lip and palate, which is characterized by: anomalies of the frontal teeth of the upper jaw, atypical form upper lateral incisors and canines, high Gothic hard palate and short soft sky, bony changes in the palatal segment (on x-ray), submucosal cleft or bifurcation of the uvula,
progenia, direct or crossbite, asymmetry of the nasal septum, scar on the upper lip and alveolar process, asymmetrical reduction of the wings of the nose. Another example is the tetralogy of Fallot, which is characterized by: anti-Mongoloid eye shape, epicanthus, hypertelorism, flat bridge of the nose, high palate, dental dystrophy, malocclusion, groove on the tongue, dysplastic ears, unusual shape skulls, clinodactyly and different lengths of the little fingers, flat feet.
In addition to the amount of MAP, it is of great diagnostic importance MAR combination. For example, Wardenburg syndrome combines: telecanthus, hyperchromia of the iris, fused eyebrows, a white strand of hair above the forehead; with Down syndrome - Mongoloid eye shape, epicanthus, transverse palmar fold, brachydactyly, clinodactyly, sandal-shaped fissure.
At the same time, the greatest diagnostic value is IDA quality, those. identification of such signs that are almost never found among healthy patients: pterygoid folds of the neck (Shereshevsky-Turner and Noonan syndromes), postaxial polydactyly (Bardet-Biedl syndrome), hypoplasia or aplasia of the breast nipple on one side (Poland syndrome), vertical notches on the lobe ear (Beckwitt-Wiedemann syndrome).
SELECTED NOSOLOGIES OF HEREDITARY SYNDROMES OF MULTIPLE CONGENITAL DEVELOPMENTAL DEVELOPMENTS
Arsky-Scott syndrome
Minimal signs: hypertelorism, brachydactyly, shawl-shaped scrotum, short stature by the end of the first year of life (stunting in 90% of cases).
Phenotype: round face, wedge-shaped hair growth on the forehead or "widow's cape" (70%), hypertelorism (95%), wide bridge of the nose (85%), short nose with outward nostrils (94%), wide filter (97%) , anti-Mongoloid eye shape (55%), ptosis (50%). Ocular abnormalities: ophthalmoplegia, strabismus, astigmatism, enlarged cornea. Also detected: hypoplasia of the upper jaw, relative progeny, slight fold under the lower lip,
abnormalities of the ears, loose joints, brachydactyly and clinodactyly of the little fingers, incomplete cutaneous syndactyly of the fingers, hyperextension in the proximal interphalangeal joints with simultaneous flexion in the distal ones, short fifth fingers with a single flexion fold, transverse fold of the palm, wide feet.
The most characteristic is a shawl-shaped scrotum (81%). Sometimes cryptorchidism, phimosis, and splitting of the scrotum are observed. Inguinal hernias have been described (66%). MR is moderate in 14% of patients. Autosomal recessive or X-linked recessive mode of inheritance. In the second case, the gene is localized in the Xq13.4 segment.
Nager's acrofacial dysostosis
Minimal signs: aplasia or hypoplasia of the radius, radioulnar synostosis, hypoplasia or aplasia of the big toe, hypoplasia of the mandible, antimongoloid ocular incision, stenosis or atresia of the external auditory canal.
Phenotype: signs of craniofacial dysostosis - Franceschetti syndrome (anti-Mongoloid eye section, underdevelopment of eyelashes, coloboma of the lower eyelid, severe hypoplasia of the lower jaw, shortening of the hard palate, hypoplasia of molar rudiments, stenosis and atresia of the external auditory canal, sometimes prearicular outgrowths, deformation and low position auricles) in combination with underdevelopment of the first finger of the hand, bones of the wrist, metacarpus, as well as shortening of the distal parts of the forearms, hypoplasia or aplasia of the radius. In the absence of the first finger, the second finger is opposed to the others and may have a double distal phalanx. Sometimes there is curvature of the fifth finger, limited mobility in the elbow joint, and absence of the second finger. Mental development is slow. Presumably an autosomal dominant mode of inheritance.
Acrocephalopolysyndactyly
Minimal signs: acrocephaly, syndactyly varying degrees. Several phenotypes are distinguished.
Apert syndrome, type I, acrocephalosyndactyly. There is synostosis of the skull bones of varying degrees (mainly the coronal suture) in combination with sphenoethmoidomaxillary hypoplasia, flat forehead, hypertelorism, anti-Mongoloid eye shape, sunken bridge of the nose, prognathism, complete fusion
II-V fingers and toes. Population frequency - 1:160 thousand, autosomal dominant type of inheritance.
Carpenter's syndrome, acrocephalopolysyndactyly, type II. Characterized by acrocephaly, specific face (telecanthus, epicanthus, flat bridge of the nose, large cheeks, low-set ears, mandibular hypoplasia), brachydactyly, syndactyly thumbs legs In adulthood - obesity, UR. Autosomal recessive type of inheritance.
Noack syndrome, acrocephalopolysyndactyly, type V. Characterized by acrocephaly in combination with wide distal phalanges of the big toes and toes. Possible syndactyly of II-III fingers and II-IV toes, accessory thumbs stop.
Pfeiffer-Robin syndrome, acrodysostosis. Characterized by small hands with short thick fingers and short nails - “three-pronged hand”, skin folds and swelling on the dorsum of the hands and feet, progressive arthritis in the distal parts of the limbs, a hypoplastic short and flat nose with an upward tip and wide nostrils, hypoplasia of the upper jaw , prognathism, open bite, delay mental development. Autosomal recessive type of inheritance.
Saetre-Chotzen syndrome, type III. Craniostenosis of varying degrees is observed, leading to skull asymmetry. Characteristic: protruding frontal and parietal tubercles, ptosis, hypertelorism, anti-Mongoloid eye shape, strabismus, fusion of soft tissues of the II-III fingers and toes, brachydactyly.
Bowen-Conradie syndrome
Minimal signs: dolichocephaly, beaked nose, microgenia, joint stiffness.
Phenotype: fetal malnutrition, dolichocephaly, protruding beak-shaped nose, deformation of the ears, microgeny, camptodactyly and clinodactyly, stiffness in the hip joints, rocker foot. Rarely, a horseshoe kidney, microcephaly, ectopia of the gastric mucosa into the esophagus, underdevelopment of the cerebellum, and cryptorchidism are detected.
The type of inheritance is autosomal recessive.
Van Der Woude syndrome
Minimal signs: mucosal cysts lower lip, cleft lip and/or palate.
Phenotype: two asymmetrically located cysts (pits) on the mucous membrane of the lower lip and a cleft of the upper lip and/or palate. Sometimes there is only one fossa, sometimes there is a fistula with a small amount mucous secretion. Population frequency - 1:80-100 thousand.
The gene is localized in segment 1q32. Autosomal dominant mode of inheritance with 80% penetrance and variable expressivity.
Williams syndrome
Minimal signs: elf face, supravalvular aortic or pulmonary stenosis, hypercalcemia.
Phenotype: small length and birth weight (on average 2700 grams); “elf face” - epicanthus, swelling of the eyelids, short nose with nostrils open forward, wide upper and small lower jaw, full cheeks, open mouth, protruding ears.
A typical face is formed by the 4th year of life. Blue irises with a star pattern are often found.
From the outside of cardio-vascular system: mitral valve insufficiency, supravalvular aortic stenosis, pulmonary stenosis, in 50% of cases - heart septal defects.
Possible hoarse voice, strabismus, craniostenosis, partial adontia, kyphoscoliosis, inguinal hernia, hypercholesterolemia. At the age of 8-18 months, hypercalcemia is sometimes detected, leading to anorexia, hypotension, constipation, polydipsia, polyuria, renal failure, and vomiting. The disease progresses with age, kyphoscoliosis, lordosis, joint stiffness, heart pathology, and urethral stenosis develop.
CP of varying degrees and mental disorders are observed.
Population frequency is 1:10 thousand. An autosomal dominant type of inheritance is assumed.
Dubowitz syndrome
Minimal signs: prenatal and postnatal retardation of physical and mental development, microcephaly, unusual face, eczematous skin lesions.
Phenotype: severe intrauterine hypotrophy, progressive microcephaly, predominance of underweight, sloping forehead, hypoplasia brow ridges, wide bridge of the nose, ptosis (often unilateral), epicanthus, telecanthus, blepharophimosis, micrognathia, high palate, cleft palate, impaired teething, multiple caries. The voice is hoarse and rough. Hair and eyebrows are sparse. Sometimes - clinodactyly, flat feet, pilonidal fossae (epithelial coccygeal ducts opening in the intergluteal fold), cryptorchidism, hypospadias, hypoplasia of the labia. The most important sign- peeling of the skin on the face and flexor surfaces of the limbs (regarded as eczema).
Characteristic: diarrhea, poor appetite, vomit. The type of inheritance is autosomal dominant.
Corneille de Lange syndrome
Minimal signs: severe delay in physical and psychomotor (mental) development, microcephaly, synophrysis (fused eyebrows), long filter, outward-turned nostrils, thin and inwardly curved upper lip, micromelia, hypertrichosis.
Phenotype: microbrachycephaly, deformed ears, synophrysis, thin eyebrows, long curled eyelashes, small nose with nostrils open forward, choanal atresia, long protruding filter, microgenia, thin upper lip, crescent-shaped mouth, high arched palate, sometimes cleft palate. Among the ocular abnormalities: astigmatism, atrophy or coloboma of the optic nerve, strabismus, myopia. Among the limb defects: acromicria, stiffness elbow joints, phocomelia and oligodactyly, clinodactyly of the fifth finger; hypoplasia of the radius and short first metacarpal bones are rarely detected. Skin: hypertrichosis, marbled skin, nipple hypoplasia. Muscle hypertonicity, weak high-pitched voice, and convulsions are noted. Defects described internal organs: heart disease, polycystic kidney disease, hydronephrosis, duplication and incomplete intestinal rotation, pyloric stenosis, inguinal and diaphragmatic hernia, cryptorchidism, genital hypoplasia. Recurrences of respiratory infections are typical.
Population frequency - 1:12 thousand. The type of inheritance has not been established.
In some cases, patients have microchromosomal rearrangements in the 3q26.3 region.
Noonan syndrome
Minimal signs: wing-shaped folds of skin on the neck, chest abnormalities, cryptorchidism, right heart defects.
Phenotype: hypertelorism, epicanthus, antimongoloid eye shape, ptosis, micrognathia, low position of the ears, folded curls on the ears, arched palate, cleft uvula, open bite and other malocclusions, myopia, keratoconus, strabismus, low hair growth on the back of the head. The neck is short, wide, and has wing-shaped folds of skin. Rib cage shield-shaped, with widely spaced nipples, the sternum protrudes in the proximal part and sinks in the distal part. Characteristics: short stature, hallux valgus elbow joints, sometimes combined with minimal deformities of the hands and feet. Kyphoscoliosis and spinal abnormalities are common. Peripheral lymphedema is possible, and less commonly, hyperelastic skin and keloid scars. In 80% of cases, defects of the right heart and large vessels are detected: pulmonary artery stenosis, open ductus arteriosus, interventricular defects and interatrial septum, tetralogy of Fallot. Cases of hypertrophy of the left ventricle and interventricular septum have been described. A number of patients have defects of the urinary system: obstructive uropathy, hydronephrosis, duplication of the pelvis, renal hypoplasia, and hirsutism.
Stigmas- these are minor developmental anomalies that are the result of exposure to various unfavorable factors. Minor developmental anomalies are often found in children with intrauterine lesions, chromosomal syndromes and hereditary diseases. Finding them in large quantities in newborns who have suffered asphyxia or intracranial birth trauma, is the basis for interpreting these conditions as secondary, developing against the background of intrauterine development disorders.
The following are the main dysembryogenetic stigmas:
Intensive shaping nervous system in the prenatal period, the synchronicity of the development of its individual elements can easily be disrupted when the fetus is exposed to unfavorable factors: 1. viral diseases mothers; 2. insufficiency of uteroplacental circulation; 3. ionizing radiation; 4. vibration; 5. teratogenic substances, etc.
The main significance in disorders of embryonic development is given not so much to the nature of the harmful factor, but to the temporary coincidence of its impact with periods of intensive formation of the nervous system - the so-called critical periods. Violation of embryonic development in the first trimester of pregnancy leads to gross malformations of the nervous system - defects in the closure of the neural tube, impaired growth and differentiation of the cerebral hemispheres and the ventricular system of the brain. Pathological effects on late stages pregnancy and perinatal period, as a rule, do not cause severe developmental defects, but lead to impaired myelination of nervous system structures, decreased dendritic growth, etc. Anomalies and malformations of the brain are often accompanied by multiple minor developmental anomalies (disembryogenetic stigmas). This is due to the fact that the skin and nervous system develop from one embryonic rudiment - the ectoderm.
High threshold stigmatization, when the number of minor developmental anomalies in one patient exceeds 5 (according to some data up to 7), indirectly indicates an unfavorable course of intrauterine development and the possibility of anomalies and malformations of the nervous system.
The most common stigmas are in the head and face: asymmetry of the skull, anomalies of the palate (high “Gothic” palate, flattened palate, bifurcated uvula), defects in the development of the upper jaw, aplasia of the lower jaw, micrognathia, prognathism. Anomalies of the auricles are extremely variable, they relate to the shape of the ear cancers] and their location. Their asymmetry, which should be regarded as a violation of the correct development of symmetrically located formations, has diagnostic significance. Numerous clinical observations show that the developmental anomalies listed above are combined with flattening of the base of the skull, often accompanied by a narrowing of the foramen magnum, and underdevelopment of the ethmoid bones.
Children with abnormalities of the facial skeleton often suffer from headaches, which are especially intensified during the period of intensive growth of the child. Shortening of the neck, disproportions of the torso and limbs are often the result of gross violations of embryonic development; Deformations of the bones and feet (wide palm, abnormal skin patterns, low position of the big toe, bident and trident on the feet) often occur in isolation in healthy people, but these anomalies with distinct constancy are included in the complexes of gross malformations. The overall incidence of congenital malformations is 15 - 42 per 1000 births. Of these, nervous system defects account for 26–28%.
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Minor developmental anomalies include such changes in the structure of a particular organ (eyes, nose, ears, limbs, skin, etc.), in which (unlike from Bar), the function of the organ remains unchanged and we are talking about minor external cosmetic defects(45). MADs are found in newborns much more often (up to 35%) than bipolar disorders (up to 7%).
The list of the most common IDAs is presented in the table 3.1-4.
Omalia of development
Continuation of the table. 3. "1-4
-flat face profile" - occipital spur (protruding - Opitz syndrome, etc. occipital bone) -two tops - Prader Willi syndrome, Ruby Nstein-Tay bi - wide bridge of nose* -trisomy 21, partial trisomy 4a, syndrome 5p-, etc. -sloping forehead* 2. Eye abnormalities:
- epicanthus* - trisomy 13, 18, 21, syndromes 4p-, 5p, 13a", Stickler syndrome, etc. - short palpebral fissures* - Dubowitz syndrome, etc. - blue sclera - narrow palpebral fissures - telecanth (lateral displacement corners of the eye)* - hypotelorism (close eyes) - hypertelorism - chromosomal syndromes: syndrome hour (wide-set eyes)* tic trisomy 4p, 4^, 7^, 9p, Yur et al. - Mongoloid eye shape -trisomy 21, Jur, syndromes 9p". 1^", Pfeiffer-Lehry syndrome: - Kolob om a century? irises* - ptosis* - partial monosomy 18p, Mobius syndrome - heterochrome and I irises - Waadenburg syndrome (different colour irises) - anti-Mongoloid eye shape - 4p- syndrome, 5p- syndrome, syndrome (the outer corners of the eyes are located partial trisomy 9p. syndrome below internal) Apert, de Lange et al. - abnormal eyelash growth (double row, etc.)" 3. Anomalies of the oral area:
- cleft uvula - Meckel's syndrome, etc. - sloping chin - thick lips with grooves - micrognathia* - trisomy 13, 18, 21 syndrome ^- and others. - high sky* - trisomy 8, 18, 21 syndrome ^-, Hallermann-Streif syndrome- fa, Triger-Collins, etc. - progeny (protruding lower jaw)* Continuation of the table. 3.1-4
- microgeny - trisomy 13 syndrome, 18, syndrome 4p", (small lower jaw) 5p", Seckel syndrome, etc.
- prognathia (speaking upper jaw) - low location* - asymmetry of ear length - fused lobe* - big ears - protruding ears - flattened ears - incomplete development ear curl - small and absent lobe - oblique direction of the ears - absence of tragus* - preauricular fistula* - parotid appendages - disturbances in the configuration of the outer ear 5. Hand abnormalities:
- short little finger - nail hypoplasia* - clinodactyly Russell-Silve syndrome
paradise etc. - syndactyly* - polydactyly* - thickening of the nail phalanges - hyperextension of fingers* - transverse palmar fold - trisomy 21 - brachydactyly* - mucopolysaccharidosis - campodactyly - Goldenhar syndrome ai AR- (stiffness of phalangeal joints) - arachnodactyly* Marfan syndrome, etc.
6. Leg abnormalities:
- syndactyly - polydactyly - wide span between the 1st and 2nd fingers - sandal-shaped gap - wide short thumb* - brachydactyly* Continuation of the table. 3.1-4
" - marked MARs, which are especially common in newborns.
In healthy newborn children, MARs are detected in 35.8% of cases, but in an amount of no more than 1-2 MARs per child. MAR is especially often found in children with congenital syndromes and hereditary diseases, when their number in the same child can simultaneously reach 5-14 (Fig. 3.1 -14, 15, 16), Detection of more than 3-4 MAP in a newborn raises the need for more careful examinations for congenital pathology.
Rice. 3.1-14. Distribution of minor developmental anomalies (poZ MAR) y newborns are normal and with pathological conditions
A - healthy children D- exogenous embryopathies
B -hereditary diseases metabolic E - connective metabolic disease
B - polygenic diseases G - genetic syndromes
G - tubulopathies 3 - chromosomal diseases
Conclusion
Congenital malformations are among those pathological conditions that a doctor constantly encounters in his practice. A significant part of congenital malformations does not present great difficulties in diagnosis, because gross external defects are so obvious that they do not raise doubts. More complex situations arise with hidden defects, the detection of which requires special research. The outcomes of congenital malformations are ambiguous, some of them are incompatible with life and lead to death. The other part distorts the function so much that it ultimately leads to disability from childhood. At the same time, there are forms of congenital malformation that are compatible with life and, with appropriate correction, allow the child to lead a normal life.
The birth of children with congenital malformation always creates dramatic situations for the patient’s family. It's hard to feel early death and disability, but a more tragic situation occurs with hereditary metabolic disorders (such as Tay-Sachs or Niemann-Pick disease), when a child born apparently healthy gradually loses previously acquired skills over the course of 1-2-3 years and dies. Unfortunately, this group of diseases often remains unrecognized. This concerns, first of all, clarification of the origins of the pathology and the absence of any pathogenetically appropriate therapy (for example, for leukodystrophies), when in front of the doctor and parents pathological process, in spite of everything, it is progressing and there is no way to stop the course of events.
Due to a certain helplessness of medicine, great value acquire timely medical and genetic counseling for a married couple and prenatal diagnosis.
Literature
1. Zieragy T.N. - Ca1a1od o^ TegaTodelyu adep^z - Tle ^llz NorYupz ituerzgGu Prgezz - Ba1- 11toge, 1976.
2. MupapTloroi(o5 M.S. - Er|s(etyu(ode o^ segPga! peguoiz susGet taNoerta1yup5 - I" Utken R.^, Bgyup 6Zh (eys); Hapdoob OT C1tyua1 Meigo1odu. Atz1erc1at, E1zey|"er 1977, 139-171.
3. Sgappit R., Se1"ap11ld| R. - 1n itego peigozolodgar11u: leigoetbguo1odu anpy els@rG)a(o-s1a5Ps)ezYupz - bep-ip RegtaYu!., 1987, 11.2, 98-111.
4. Bochkov N.P., Zhuchenko N.A., Kirillova E.A., Volkov I.K., Vasilyeva G.L., Popova L, D. - Monitoring of congenital malformations - Ros, western perinat. iped., 199E 2, 20-25.
5. (-euele M., Tiyepore ABOUT., T^eaPe ^ - Ez5epPa)z o^ neopa1a1 teaste - B1ac((U/e115c1ep(|(,:
6. KigsgupzK! T. - SopdepLa! ta^ogtayope - In the book; Meopa1a[-Replaga1 MesIste. - T^g S.U.MosbySoglralu.ZM-oshz, 1987, 253-280.
7. 8ute^.,^L/a^N^pol^.-Neui^a[^u^eNe^es^s^pzrop(aleoisaboP^opz~At.^.Me(^,^ener-1986,25,327 -333,
8. KIne^, 3(eSH2-, YezagM. - SopserIopY LICE - Ox^ogy Chtuerz^Rgezz, 1989.
9. Burdulm G.M., Frolova O.G. - Reproductive losses. - M.,"Triad-X", 1997.
10. Kirillova E.A. - Clinical and genetic aspects disorders of the reproductive system of women - Abstract. doc. diss., M., 1989.
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Hello!!!
Today I had an unscheduled ultrasound of the fetus at 24-25 weeks of pregnancy. The ultrasound doctor wrote in her conclusion that it cannot be ruled out that the aorta is displaced to the right and is located above the interventricular septum. No further pathologies or developmental delays were found. Please tell me, is this an anomaly in the development of the heart or is the period still short and everything can work out?
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