MALFORMATIONS

From Big Medical Encyclopedia

MALFORMATIONS (synonym inborn defects) — the permanent morphological changes of body or an organism which are going beyond variations of their structure and resulting vnutriutrobno from disturbances of development of a germ, a fruit or sometimes after the birth of the child as a result of disturbance of further formation of bodies. Et al. (1978) expand with Berry (S. of Berry) this concept, suggesting to consider P. river as «a deviation of a form, chemical composition or function». Smith (D. W. Smith, 1975), on the contrary, carries to P. the river only «primary structural defects which are result of the localized wrong morphogenesis».

Uglinesses call P. of rubles who disfigure a part of a body or all body and are found already at external examination. Generally it is defects of c. the N of page who are followed by a disfiguration of the person and a neurocranium. E.g., a cyclopia (cyclocephalia) — presence of one or two merged eyeglobes in the only orbit located on the centerline of the person, an anencephalia — lack of a great brain, bones and soft tissues of a skull, an exencephaly — lack of a part of a calvaria and soft covers of the head therefore hemicerebrums eminate in the form of the nodes covered with a soft cover of a brain; malformations of extremities in the form of dizmeliya (a partial and total aplasia of tubular bones). Proceeding from the principles of a deontology, in a wedge, it is reasonable to practice to avoid the use of the term «uglinesses». Anomalies of development (small defects) more often the rubles who are not followed by dysfunctions of body call P. (e.g., the deformations of auricles which are not disfiguring the patient and not affecting perception of sounds). The terms «inborn uglinesses», «dysplastic diseases», «dizontogeniya», «teratoza» offered by certain researchers were not widely adopted.

Items of river are known from an extreme antiquity. We were reached Ancient Egyptian (St. 5 thousand years ago) by the image of the patient with a chondrodysplasia. In the Babylon cuneiform writing (3800 — 2000 years BC) there is a table, in a cut 62 types of P. of river are listed. One of the first books devoted to P. by river [E. Licetus «De monstris causis, natura et differentiis»], appeared in 1616. In Russia the foundation was laid for a research P. of river by Peter I (1718) decree on creation in St. Petersburg of «The museum of urodlivost» and connected with K. F. Wolf and K. M. Ber's names. The doctrine about P. of river was selected in independent science — teratology (see) — after in 1822 Mr. Geoffroi St E. G. Saint-Hilaire applied an experimental method of studying of origins of P. of river.

Frequency of the birth of children with P. of river is definitely not established. Most of researchers estimate this indicator at 2% that is hardly fair as total population frequency only of heart diseases, Mekkel's diverticulum and doubling of ureters makes apprx. 4%. P.'s frequency of river at the children who died in the perinatal period fluctuates and, according to most of researchers, steadily increases.

In P.'s emergence by the river is important mutation (see). As a result of genovariations monomutant P. of river (17 — 20%) develop; chromosome and genomic mutations — chromosomal diseases (10 — 12%), owing to the combined influence of genovariations and factors external (in relation to a germ) Wednesdays — multifaktorial-ny P. of river (40 — 65%). Under the influence of teratogens develop blasto-, embrio-and fetopathies (3 — 5%). The vast majority of P. of river is connected with hereditary pathology and only 3 — 5% are induced directly by teratogens (see. Teratogenesis ). Of river

the mutation of one gene which occurred in sex cells of parents or more remote ancestors of the patient is the cornerstone of monomutant P. Transfer of this gene from parents to children submits to Mendel's laws (see. Mendel laws ). Depending on a mode of inheritance such P. rubles can be dominant, napr, some forms of a polydactylia, a polycystosis of kidneys of adult type, Marfan's syndrome, and recessive, napr, an infantile polycystosis of kidneys, Mekkel's syndrome. Dominant nasleduye-mye P. of river — the investigation of either a new mutation, or transfer of the mutating gene from one of parents who usually have similar P. of river. At recessive inheritance parents of the patient are healthy, but both are carriers of the changed gene. The special group P. of river is made by defects with the H-linked mode of inheritance. These rather rare P. of river, napr, obstructive hydrocephaly, are observed usually at the males who received the pathological gene localized on X-chromosome from mother (The X-linked recessive P. by river). The dominant inherited rubles H-linked by P., napr, rotolitsepaltsevy a syndrome of the I type, usually occur at female persons as the male germ with such P. of river is impractical. Monogenic forms P. of river are presented by a large number nozol, forms.

Chromosomal diseases — the multiple P. of the river induced by numerical or structural mutations of chromosomes (see. Chromosomal diseases ). At the child with any chromosomal disease about 20 malformations can be observed. The ruble creates such P.' complex quite specific to the majority of chromosomal diseases patol, a morphotype. Tens of chromosomal diseases caused by mutations practically of any chromosome are known.

P.'s emergence by the river of multifactorial group requires hereditary predisposition, a cut is caused by group patol, the genes which reached a certain (superthreshold) concentration and influence of adverse environmental factors. P.'s most of river of heart, an anencephalia, an inientsefaliya (an aplasia of a part or all occipital bone therefore the most part of a brain is located in the field of a back cranial hole and partially in an upper part of the expanded vertebral channel), spinal hernias, a prozentsefaliya (a nerazde-leniye of a front brain bubble on big hemispheres), neobstruktiv-ny hydrocephaly, the majority of crevices of a lip and sky, an inborn pylorostenosis, a clubfoot, megacolon, dislocation of a hip, a dysplasia of kidneys, etc. concerns to this group.

From several hundred teratogens known in an experimental teratology, the reason of G1. rubles of the person are only the few. In particular, some viruses (e.g., rubellas, an inklyuzionny cytomegaly, a lymphocytic choriomeningitis), protozoan infections (Toxoplasmosis), listeriya, ionizing radiation in a total dose on a fruit more than 15 r, amniotic tyazh, some pharmaceuticals (a thalidomide, warfarin, cytostatics, progestin, etisteron, methyltest OST-ron), ethyl alcohol, and also such disease as a diabetes mellitus concern to those. Part of them induces quite specific syndromes (talidomidny, alcoholic, a diabetic embryopathy, a rubella, a medicamentous false hermaphroditism).

The origins

Origins of malformations are studied insufficiently. Consider that P.'s formation by the river results from disturbance of processes of reproduction, migration and a differentiation of cells, death of separate cellular masses, delay of their rassasyvaniye, disturbance of adhesion of fabrics. The stop or delay of reproduction of cells leads to an aplasia or a hypoplasia of body, disturbance of merge of separate embryonal structures, is normal to the events during strictly certain periods. In cases of low proliferative activity of cells the contact between embryonal structures is late. As a result of changes of migration of cells an aplasia and a number of difficult defects can develop a heterotopy. E.g., heavy symmetric facial clefts are formed as a result of disturbance of migration of cells of a neuroectodermal crest in maxillary shoots. Change of a differentiation of cells can happen during any period of an embryogenesis and be the cause of an agenesia of bodies, them morfol. and functional immaturity, and also a persistirovaniye of embryonal structures, napr, a nerazde-leniya as it is observed at a prozentsefaliya. The delay fiziol, disintegration of the cells which are dying off in the course of an embryogenesis (e.g., at a rassasyvaniye of interdigital membranes, a rekanalization of an intestinal tube and opening of natural foramens), can lead to a syndactylia, an atresia, a stenosis. Disturbance of the adhesive mechanism, i.e. pasting, deduction and accretion of embryonal structures, as well as insufficiently active proliferation. is the reason of many dysraphias (e.g., P. of the rubles connected with not - closing of a neurotubule). Nek-ry P.' formations by the river are the cornerstone the circulator frustration caused tromoozy, a prelum, hemorrhage. The teratogenic effect of infections is more often connected with cytolytic operation of the activator.

Formation of most of P. of river happens during the first 8 — 10 weeks of pregnancy. Sensitivity of an embryo to disturbing factors in these terms is various. According to P. G. Svetlov, allocate two intervals of time of hypersensitivity which call critical periods. The first of them at the person is the share of the end of the 1st — the beginning of the 2nd week of pregnancy. Action of a harmful factor often leads at this time to death of a germ. Similar influence in the second critical period (3 — the 6th week of pregnancy) induces P. of river more often. For establishment of a possible etiology of P. of river time of action of an estimated harmful factor is compared not with critical, and with the teratogenetic termi-national ion period (TTP) as each P. the river has the TTP not always matching a critical period. This term offered in 1906 Mr. of Shvalbe (E. Schwalbe), is understood as a deadline, during to-rogo action of the harming factor can cause P. of river E.g., TTP of two-chamber heart proceeds till 34th day of pregnancy, an aplasia of an interventricular partition — till 44th day, defect of an interatrial partition — till 55th day of pregnancy. TTP for a persistirovaniye of an arterial channel (a botallov of a channel), a cryptorchism, many P. of river of teeth goes beyond pregnancy since final formation of these structures does not come to the end during pre-natal development.

Classification

rubles divide P. on etiol, to the principle, time and subject to damage, the sequence of emergence, prevalence and localization of changes. Depending on an object and time of influence of teratogens the rubles who developed as a result allocate P. gametopathies (see), blastopatiya, embryopathies (see) and fetopathies (see). Depending on the sequence of emergence distinguish primary P. of the river (directly caused by influence of a pathogenic factor) and secondary, being a complication of primary. E.g., spinal hernia (primary P. of river) can be complicated by a clubfoot (in this case secondary P. river). On prevalence in an organism primary P. rubles subdivide on isolated (single, local) — localized in one body, system — P. river within one system (e.g., a chondrodysplasia, an arthrogryposis), multiple — P. of river of bodies of two and more systems (e.g., a combination of a crevice of a lip to a polydactylia). Rubles classify the isolated and system P. by the anatomic principle of division of a body of the person into systems of bodies (malformations of c. N of page, heart and vessels, respiratory system etc.). Rubles divide multiple P. into syndromes and not classified complexes. Syndromes call steady combinations of primary P. of river induced by the general etiol, a factor (a mutation or teratogenic influence). When the complex of the rubles found in sick P. does not keep within one of the known syndromes, use the term «not classified complex of inborn defects» or «the multiple not specified malformations».

Rubles refer the following disturbances of development to P. Aplasia (see) — inborn absence of body. Inborn hypoplasia (see) — an underdevelopment of body, the shown deficit of the weight (weight) or reduction of the sizes of body exceeding a deviation in two sigma from average values for this age. Inborn hyperplasia (see) — the increased weight (weight) or the sizes of body due to increase in quantity (hyperplasia) or volume (hypertrophy) of cells. A macrosomia (giantism) — the increased length of a body. A heterotopy — existence of cells or fabrics of one body in another or in those zones of the same body where they shall not be. A heterotopy) fabrics quite often call a choristia. A heteroplasia — disturbance of a differentiation of cells within the same fabric (e.g., existence of cells of a flat epithelium in Mekkel's diverticulum). An ectopia — an arrangement of body in the unusual place.

Doubling, and also increase in number of bodies or its parts, napr, doubling of a uterus, a double aortic arch is possible. Existence of additional bodies is usually designated the Greek prefix poly-, napr, by a polysplenia, a polydactylia. A stenosis (see. Stricture ) — narrowing of the channel or opening. Atresia (see) — lack of the natural channel or an opening. Not division (merge) of bodies or two symmetrically or asymmetrically connected monozygotic twins is possible. Not divided twins call pagam, adding the Latin term designating the conjunction, napr, torakopag — the symmetric twins connected in a thorax. At asymmetrically connected twins one of twins it is developed normally (autozit), and another is underdeveloped (parasite). Treats asymmetric twins and it is rudimentary the developed second fruit not connected with the first. Such fruits usually have no head (acephalia), heart (an acardia, a holocardia) or any other bodies. Not divided fingers are called syndactylia (see), the lower extremities which merged among themselves — a simpodiya. Persistirovaniye — preservation of embryonal structures, napr, the centers of a metanephrogenic blastema in a kidney of a newborn, arterial channel at the child is more senior than 3 months. A dysraphia (arafiya) — not fusion of embryonal cracks, napr, heylognatopala-toskhiz — a crevice of an upper lip, upper jaw and the sky, a craniorrhachischisis — the nesmykaniye of bones of a skull and backbone which is usually followed by cranial and spinal hernias (see. Brain , Spinal cord ).

Items of river of a musculoskeletal system on frequency are high on the list among all P. of river, at the same time 3/4 they are the share of P. to river of extremities. The international classification of P. of river of a musculoskeletal system (1975) includes 7 groups.

I. The anomalies resulting from insufficiency of formation of parts of extremities. The following P. of river of extremities enter into this group. An amelia — total absence of an extremity (excepting a shoulder girdle and a basin). Distinguish a top and bottom amelia, in particular lack of two upper extremities (abrakhiya), one upper extremity (monobrachia), two lower extremities (opus), one lower extremity (monoapus). Fokomeliya (tyuleneobrazny extremities) — lack of proximal and (or) middle parts of an extremity and the corresponding joints (humeral, coxofemoral). Distinguish proximal, distal and full fok mistletoes iyu. A proximal fokomeliya — lack of a shoulder or hip, distal — lack of a forearm (a radioulnar-ny form) or shins (a tibiofibulyarny form), a full fokomeliya — lack of a shoulder and forearm or hip and shin. Respectively quite created brush or foot can directly depart from a trunk (a full fokomeliya), to connect to it by means of the remained bones of a forearm, a shin (a proximal form) or to be attached to a shoulder, a hip (a distal form). Fokomeliya is one - and bilateral, sometimes all four extremities are involved in process. Peromeliya — option of the fokomeliya which is combined with an underdevelopment of brushes or feet. Distinguish full (the hand or a leg is absent, the relevant department of a trunk comes to an end with one rudimentary finger or a skin ledge) and incomplete (the shoulder or a hip is underdeveloped, comes to an end also with one rudimentary finger or a skin ledge) forms. Meet also beam and elbow talipomanus (see), an aplasia of a tibial bone, an aplasia of a fibular bone, an adaktiliya — lack of fingers, an aphalangia — lack of phalanxes, a monodactylism — existence of one finger on a brush or foot, an akheyriya — lack of a brush (see. Brush ).

A cleft hand (an ektrodaktiliya, a kleshneobrazny brush, «a brush of a lobster») — an aplasia of the central components of a brush (fingers and quite often metacarpal bones) with a furrow (crevice) on site the absent bones. Allocate typical and atypical forms. The typiform is characterized by an aplasia of the III finger and (quite often) corresponding metacarpal bone, and also (sometimes) a distal number of bones of a wrist that causes existence of a deep crevice. The atypical crevice is characterized by an underdevelopment (more rare absence) average manual components of a brush or foot. At an atypical form a crevice superficial, but wide; sometimes it has an appearance of excessively wide interdigital interval. Splitting of the right brush meets more often. This P. of river can be followed syndactylia (see), a brachydactyly (korotkopat an awn), a clinodactyly and the split foot. Quite often the cleft hand meets at rotopaltsevy anomalies, maxillofacial synostoses, a syndrome of a subnodal pterygium, etc. On the nature of inheritance allocate two types of a cleft hand: 1) with continuous involvement in process of foot (dominant type) and 2) without defeat of foot (recessive type).

II. The anomalies resulting from an insufficient differentiation of parts of an extremity. P. of river of a shovel (a carinate shovel, the raised shovel) concern to them, synostoses (see), syndactylias, brachydactyly, inborn clubfoot (see), congenital dislocation of a hip (see. Hip joint ), arthrogryposis (see), a clinodactyly — shortening of an average phalanx of fingers of brushes (is more often than the V finger), the rubles who are usually a compound component of syndromes of multiple P., especially chromosomal.

Kamptodaktiliya (kampilodaktiliya) — a flexion contracture of proximal interphalangeal joints of fingers of a brush. Any finger, except the first can be involved in process. Meets seldom.

A symmelia (a simpodiya, a simme-liya, a syndrome of caudal regression) — merge of the lower extremities. Merge can concern soft tissues (more often) of nek-ry long tubular bones, and also be followed hypo - and (or) an aplasia of separate bones of extremities and a basin. Feet can be absent (sym-pus apus), to be created two (sympus dipus) or one foot (sympus monapus). Sometimes there is one rudimentary foot with the only finger. The symmelia is followed by an aplasia of outside and internal generative organs, an aplasia of uric system, an atresia of an anal orifice and a rectum, an aplasia of one umbilical artery.

III. Anomal and and, caused by doubling: a polydactylia, a diplopodiya — doubling of foot, a polymelia — increase in number of the lower extremities. The polymelia can be symmetric (quadri-pus) and asymmetric (tripus), the river, incompatible with life is usually combined with P.

IV. The anomalies caused by overgrowth. Include a macrodactyly and giantism of an extremity (partial giantism, a unilateral macrosomia, a hemihypertrophy) — extremely rare P. the ruble who is shown unilateral increase relatively in proportion to the developed extremity. Anomaly of a rostkovy cartilage is the cornerstone of it (giperkhondroplaziya).

V. The anomalies caused by insufficient growth. Their number includes the anomalies which are shown a hypoplasia of various departments of bones of extremities.

VI. Inborn banners — a malformation of amnion in the form of fabric tyazhy, passing in a fruit bed and connecting among themselves a fruit surface of an afterbirth with a surface of a fruit, different points of a fruit surface of an afterbirth and several points of a surface of a fruit (see. Amniotic threads, banners, unions ).

VII. Generalized (system) skeletal deformations. Disturbance of an embryogenesis of connecting fabric, including a bone tissue is the cornerstone of them. Treat this group chondrodysplasias (see), osteodysplasias (see) and hyperostoses (see).

P.'s signs of river and the principles of their treatment in many respects depend on extent of dysfunction and importance of the struck body for life, and also on the joined complications. Gross violations of vitals, including the majority of the chromosomal diseases caused by pathology of autosomes are detailed. Apprx. 40% of malformations some are shown only in process of development of the child, napr, the unilateral areniya, an aplasia of a gall bladder, can proceed asymptomatically.

Rubles korrigirut P.'s most in the operational way. At correction of separate defects, napr, congenital dislocation of a hip, apply the conservative or combined treatment. At P. rubles, directly life-threatening the child, napr, at intestinal impassability, perform an immediate surgery. In most cases surgery is performed aged 6 months (a crevice of a lip) or at even more advanced age (P. are more senior than river of heart and large vessels, P.'s most of river of urinogenital system, the musculoskeletal device).

Prevention is subdivided into mass and individual (family). Mass prevention — a package of measures, directed to protection of the person against action mutagen and teratogens, environmental control. Individual prevention is performed by doctors medicogenetic consultations (see) which define genetic risk, give help to a family in making decision on the birth of the child and, at an opportunity, carry out prenatal diagnosis of a condition of a fruit.

See also Kiyematopatiya and articles devoted to separate malformations, e.g. Anorkhiya , Gynatresia , Epispadiya etc., to both bodies and parts of a body, e.g. Eye , Thorax , Stomach , Knee joint , Lungs , Backbone etc.



Bibliography: Abalmasova E. A. and Luzina E. V. Inborn deformations of a musculoskeletal system and reason of their origin, Tashkent, 1976; M. V Wolves. Diseases of bones at children, M., 1974; Gulkevich Yu. V., Lazyukg. And. and Kulazhenkov. P. Bases of a teratology in modern aspect, Arkh. patol., t. 33, No. 2, page 9, 1971; L and z yu to G. I. Znacheniye of diagnosis of inborn malformations in practice of pathologists, in the same place, t. 42, No. 7, page 24, 1980; M and to yu with and to V. A. Ancestral features of the person, the lane with English, M., 1976; Not Mendelian malformations, models on animals and their value for studying of diseases of the person, Bulletin WHO, t. 55, No. 4, page 473, 1978, bibliogr.; A teratology of the person, under the editorship of G. I. Lazyuk, M., 1979; Fraser F. Page of Prevention of birth defects, Teratology, v. 17, p. 193,1978; Guzanin S. Mal-form£cie horntch koncatin, Acta chir, orthop. Traum. Cech., sv. 46, s. 364, 1979; Kay H. The proposed international terminology for the classification of congenital limb deficiencies, Develop. Med. Child Neurol., v. 17, suppl. 34, 1975; Smith D. W. Classification, nomenclature and naming of morphologic defects, J. Pediat., v. 87, p. 162, 1975.


G. I. Lazyuk.

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