Centric fission of chromosome No. 4 in the mother of two patients with trisomy 4p

Abstract
Centric fission of chromosome No. 4 was found in the healthy mother of two children with trisomy 4p. The two telocentrics derived are stable and show no evidence of fusing again. the 2:3 ratio of unbalanced offsprings born to the proposita indicates that, contrary to the evidence emerging from studies in other species, the risk for the production of unbalanced gametes is high.