Incomplete trisomy 22. II. Familial trisomy of the distal segment of chromosome 22q in two brothers from a mother with a translocation, t(6;22)(q27;q13).

Two brothers with duplication of the distal segment of 22q inherited from a t(6;22)(q27;13) translocation carrier mother presented with intrauterine growth retardation, congenital hydrocephalus, cleft palate, genital hypoplasia with cryptorchidism and hypospadias, and similar facial features including mongoloid position of eyeaxes, hypertelorism, small nose with prominent bridge, prominent upper lip, and small mandible. In addition the second sib revealed renal hypoplasia, arrhinencephaly and pentalogy of Fallot. The patients died at ages eight days and one day, respectively. The two brothers appear to be the first instances of familial trisomy 22q13 leads to qter.