Meiotic segregation in familial reciprocal translocation t(8q;22q).

We studied the chromosomes of a mentally retarded boy with minor anomalies and of his parents using a G-band stained high-resolution chromosome method. This documented dup (8q24.1 = to 8qter) and dup(22pter = to 22q11.2) in the boy due to a maternal balanced reciprocal translocation of chromosomes 8 and 22 and 3:1 disjunction during meiosis I. The karyotype of the boy is 47,XY, +der(22) (22pter = to 22q11.2::8q24.1 = to 8qter). The der(22) was involved in satellite associations and stained positively with AgNO3 in mother and child. The case is compared to similar cases in the literature and the function of the small acrocentric marker chromosome during meiosis is discussed.