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Défauts congénitaux de structure chez les jumeaux - Diversité, étiologies, conseil génétique


Schinzel, Albert (1985). Défauts congénitaux de structure chez les jumeaux - Diversité, étiologies, conseil génétique. Schweizerische Rundschau für Medizin PRAXIS, 74(14):351-357.

Abstract

Congenital structural defects are at least 2.5 limes more frequent among monozygotic twins than among fraternal twins and singletons. This excess is mainly due to the following 4 etiological groups of defects: malformations and malformation complexes, disruptions and disruptive complexes, intrauterine growth retardalion caused by twin transfusion, and deformations and deformation complexes due to lack of space during the third trimester. The later the twin separation occurred and the earlier a malformation is determined during embryogenesis, the more frequently it occurs in monozygotic twins versus singletons and dizygotic twins. The majority of affected twin pairs are discordant for malformations, and full concordance is very rare. These observations allow to conclude that twin formation and occurrence of an early malformation in one or both partners may be due to one and the same early disturbance of development. Disruptions are mainly found in surviving partners of a twin deceased in utero with a common placenta. They arise through intravascular coagulation and necrosis in the deceased twin and his placental area and subsequent embolization through placental anastomoses in the circulation of the surviving twin, especially in his cerebral and mesenterial arteries. These embolizations most frequently lead to microcephaly, porencephalic cysts and intestinal atresia. The increase of the incidence of congenital structural defects in monozygotic twins is mainly caused by non-genetic factors, and consequently, after such an event, the recurrence risk is low for siblings and offspring of an affected individual.

Abstract

Congenital structural defects are at least 2.5 limes more frequent among monozygotic twins than among fraternal twins and singletons. This excess is mainly due to the following 4 etiological groups of defects: malformations and malformation complexes, disruptions and disruptive complexes, intrauterine growth retardalion caused by twin transfusion, and deformations and deformation complexes due to lack of space during the third trimester. The later the twin separation occurred and the earlier a malformation is determined during embryogenesis, the more frequently it occurs in monozygotic twins versus singletons and dizygotic twins. The majority of affected twin pairs are discordant for malformations, and full concordance is very rare. These observations allow to conclude that twin formation and occurrence of an early malformation in one or both partners may be due to one and the same early disturbance of development. Disruptions are mainly found in surviving partners of a twin deceased in utero with a common placenta. They arise through intravascular coagulation and necrosis in the deceased twin and his placental area and subsequent embolization through placental anastomoses in the circulation of the surviving twin, especially in his cerebral and mesenterial arteries. These embolizations most frequently lead to microcephaly, porencephalic cysts and intestinal atresia. The increase of the incidence of congenital structural defects in monozygotic twins is mainly caused by non-genetic factors, and consequently, after such an event, the recurrence risk is low for siblings and offspring of an affected individual.

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Additional indexing

Other titles:Congenital development defects in twins: spectrum, etiology, genetic counselling
Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Institute of Medical Genetics
Dewey Decimal Classification:610 Medicine & health
570 Life sciences; biology
Scopus Subject Areas:Health Sciences > General Medicine
Uncontrolled Keywords:Genetics, Genetics (clinical)
Language:French
Date:1985
Deposited On:04 Apr 2024 09:25
Last Modified:05 Apr 2024 20:00
Publisher:Hallwag
ISSN:1013-2058
OA Status:Closed