Parental origin and meiotic stage of non-disjunction in 139 cases of trisomy 21.
The parental origin and the meiotic stage of non-disjunction have been determined in 139 Down syndrome patients with regular trisomy 21 and in their parents through the analysis of DNA polymorphism. The meiotic error is maternal in 91.60% cases and paternal in 8.39% of cases. Of the maternal cases, 72.41% were due to meiosis I errors (MMI) and 27.58% were due to meiosis II errors (MMII). Of the paternal cases, 45.45% were due to meiosis I (PMI) and 54.54% were due to meiosis II (PMII). The mean maternal ages were 31.6 +/- 5.3 (+/- SD) years in errors from MMI, 32.3 +/- 6.4 years in errors from MMII, 31.4 +/- 4.6 years in errors from PMI and 29.5 +/- 2.7 years in errors from PMII. No significant statistical differences were observed between maternal and paternal errors, further supporting the presence of a constant chromosome 21 non-disjunction error type.
Ballesta
F
F
Genetics Service, Hospital Clínic, Barcelona, Spain.
Queralt
R
R
Gómez
D
D
Solsona
E
E
Guitart
M
M
Ezquerra
M
M
Moreno
J
J
Oliva
R
R
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002891:Chromosomes, Human, Pair 21; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D018392:Genomic Imprinting; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008540:Meiosis / Q000235:genetics; D009630:Nondisjunction, Genetic; D010290:Parents; D011110:Polymorphism, Genetic; D012744:Sex Ratio; D014314:Trisomy