THE D1 trisomy syndrome is usually characterized by a rather stable complex of physical anomalies.1 The cytogenetic abnormality most frequently associated with it is an extra member of group D (13-15), the large acrocentric elements, yielding a modal number of 47 chromosomes. In some cases, patients with the syndrome have only 46 chromosomes and are carriers for a D/D translocation. However, they still possess most of the genetic information of 47 chromosomes. Reports of such D1 trisomic translocation carriers have been reviewed by Hecht et al2 and Pinkerton and Cohen.3 Although almost all have been sporadic in nature, ie, the translocation chromosome was not inherited from either parent, a few familial cases have been observed.3 We wish to report a sporadic case of D1 trisomy in which the proposita possessed a modal number of 45 chromosomes and carried two D/D translocation chormosomes.
Cohen MM, Takagi N, Harrod EK. Trisomy D1 With Two D/D Translocation ChromosomesReport of a Case. Am J Dis Child. 1968;115(2):185–190. doi:10.1001/archpedi.1968.02100010187006