The unbalanced offspring of the male carriers of the 11q;22q translocation: nondisjunction at meiosis II in a balanced spermatocyte.
Carriers of the standard translocation t(11;22) (q23.3;q11.2) produce only one type of unbalanced offspring, a tertiary trisomy resulting into the karyotype 47,XX or XY, +der(22)t(11;22)(q23.3;q11.2), usually derived from the mother. The exception is one single patient 47,XY,t(11;22)(q23.3;q11.2), +der(22)t(11;22) (q23.3;q11.2)pat. We report a second case with the same karyotype, also of paternal origin. Thus, the rare unbalanced offspring of a carrier father (only 5 cases known) may receive a supernumerary der(22), as a consequence of tertiary trisomy, but also as a consequence of nondisjunction at meiosis II of a balanced spermatocyte.
Simi
P
P
Laboratorio di Citogenetica, Universitá di Pisa, Italy.
Ceccarelli
M
M
Barachini
A
A
Floridia
G
G
Zuffardi
O
O
D002871:Chromosome Banding; D002880:Chromosomes, Human, Pair 11; D002892:Chromosomes, Human, Pair 22; D006580:Genetic Carrier Screening; D006801:Humans; D007621:Karyotyping; D008214:Lymphocytes / Q000502:physiology; D008297:Male; D008540:Meiosis; D009630:Nondisjunction, Genetic; D013090:Spermatocytes / Q000166:cytology / Q000502:physiology*; D014178:Translocation, Genetic