[Detection of gonadal mosaicism in parents of children with Down syndrome].
The paper presents results of a revision of data of both conventional chromosome testing and a study of cytogenetic (QFQ) markers in families with Down syndrome. Retrospective analysis of 151 families found eight families with a carrier of gonadal mosaicism. In all cases, the mother was younger than 35 years old. Therefore a prevalence of parental mosaicism in young couples was estimated to be 6.5% (8/123). Conventional diagnostic testing, not followed by analysis of segregation of QHQ markers, would have resulted in a prevalence of only 1%. A comparison of the results ofcytogenetic analysis with those expected using molecular polymorphisms suggests that cytogenetic testing cannot be entirely replaced by molecular testing. A combination of both methods should be applied when gonadal mosaicism is suspected.
Kovaleva
N V
NV
Tahmasebi-Hesari
M
M
D000328:Adult; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D005817:Genetic Counseling; D006801:Humans; D008297:Male; D008423:Maternal Age; D009030:Mosaicism; D010331:Paternal Age; D010375:Pedigree; D012730:Sex Chromosomes / Q000235:genetics*; D014314:Trisomy