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 → 8qter) and dup(22pter → 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 → 22q11.2::8q24.1 → 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.