Since the usefulness of chromosome differential banding techniques has become fully established, several descriptions of chromosome 10 short arm trisomy have been published (Schleiermacher et al., 1974; Roux et al., 1974; Cantu et al., 1975; Grosse et al., 1975; Moric-Petrovic et al., 1976; Turleau et al., 1976; Johnson et al., 1977; Yunis and Lewandowski, 1977). The present report deals with a mother who is a carrier of a reciprocal translocation between chromosome 22 and 10, which has resulted in two children with a 10p trisomy.