DNA polymorphism analysis in families with recurrence of free trisomy 21

Journal Article · Sun Nov 01 04:00:00 EST 1992 · American Journal of Human Genetics; (United States)

OSTI ID:6975170

Pangalos, C G; Rethore, M O; Blois, M.C. de; Prieur, M; Raoul, O; Lejeune, J; Talbot, Jr, C C; Lewis, J G; Adelsberger, P A; Peterson, M B ^[1]

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1. and others

The authors used DNA polymorphic markers on the long arm of human chromosome 21 in order to determine the parental and meiotic origin of the extra chromosome 21 in families with recurrent free trisomy 21. A total of 22 families were studied, 13 in which the individuals with trisomy 21 were siblings (category 1), four families in which the individuals with trisomy 21 were second-degree relatives (category 2), and five families in which the individuals with trisomy 21 were third-degree relatives, that is, their parents were siblings (category 3). In five category 1 families, parental mosaicism was detected, while in the remaining eight families, the origin of nondisjunction was maternal. In two of the four families of category 2 the nondisjunctions originated in individuals who were related. In only one of five category 3 families, the nondisjunctions originated in related individuals. These results suggest that parental mosaicism is an important etiologic factor in recurrent free trisomy 21 (5 of 22 families) and that chance alone can explain the recurrent trisomy 21 in many of the remaining families (14 of 22 families). However, in a small number of families (3 of 22), a familial predisposing factor or undetected mosaicism cannot be excluded. 34 refs., 3 figs., 1 tab.

• OSTI ID: 6975170
• Journal Information: American Journal of Human Genetics; (United States), Journal Name: American Journal of Human Genetics; (United States) Vol. 51:5; ISSN AJHGAG; ISSN 0002-9297
• Country of Publication: United States
• Language: English

Related Subjects

550400* -- Genetics
59 BASIC BIOLOGICAL SCIENCES
ANEUPLOIDY
CHROMOSOMAL ABERRATIONS
CHROMOSOMES
HUMAN CHROMOSOME 21
HUMAN CHROMOSOMES
MENTAL DISORDERS
MUTATIONS
ORIGIN
PLOIDY