Phenotypic manifestation in a child with 46,X,der(X)t(X;1) (q24;q31.1)

We report on a 5-year-old girl with multiple congenital anomalies, developm ental delay, and a de novo unbalanced translocation between chromosomes X a nd 1[46,X,der(X)t(X;1)(q24;q31.1)] resulting in partial trisomy to and part ial monosomy Xq, The karyotype shows inactivation of the abnormal X chromos ome. The translocated portion of 1q remains active in the tissues studied. This is the third case report with partial trisomy 1q and partial monosomy Xq, However, it is the first with specific breakpoints at 1q31.1 and Xq24. (C) 2000 Wiley-Liss, Inc.