Reciprocal translocations between acrocentrics: segregational analysis in twenty-nine families with unbalanced progeny.
This study comprises 29 families with 42 unbalanced offspring in which reciprocal interacrocentric translocations (RIATs) were identified by banding. The observed unbalances were due to adjacent-1 (42.9%), adjacent-2 (28.6%) and 3:1 (28.6%) segregations. The concordance between the observed and expected segregations was 85.7% according to the Jalbert et al. (1980) criteria. 17.2% of the RIATs led to unbalances by 2 different segregations. 78.6% of the cases were maternal in origin. The overall incidence of spontaneous abortion was 37%. Corrected recurrence risks of unbalanced liveborn offspring for female and male carriers were seemingly similar: 17.8% and 12.5% respectively. These data indicate that RIATS exhibit (as distinctive features) an approximate 4:3:3 ratio for adjacent-1, adjacent-2 and 3:1 segregations, and a proneness to produce unbalances by different segregations.
D000022:Abortion, Spontaneous; D002877:Chromosomes, Human; D005260:Female; D006801:Humans; D007621:Karyotyping; D008297:Male; D011247:Pregnancy; D012306:Risk; D014178:Translocation, Genetic