Adult with an interstitial deletion of chromosome 10 [del(10)(q25.1q25.3)]: Overlap with Coffin-Lowry syndrome

We recently evaluated a mentally retarded 48 year old man found to have a c ytogenetic deletion of chromosome 10 [46,XY,del(10)(q25.1q25.3)]. Of intere st, he shares many clinical findings with those described in Coffin-Lowry s yndrome (CLS), These include severe mental retardation, short stature and a coarse facial appearance with widely spaced eyes, and patulous lips. He al so had an extra transverse hypothenar crease, a finding that is seen in CLS , Furthermore, he has characteristic radiographic hand findings described i n 95% of patients with CLS, The CLS gene, located at Xp22.2, has recently been identified, and mutation s in the Rsk-2 gene have been identified in several CLS patients. Rsk2 is p art of a gene family implicated in cell cycle regulation through the mitoge n-activated protein (MAP) kinase cascade. None of the currently recognized components of this pathway maps to the region deleted in our patient, nor a re we able to identify any likely candidate genes in the deleted region, al though several G protein coupled receptors have been cloned from the region . This patient's findings have some overlap with those seen in CLS, suggestin g that a gene involved in MAP kinase signaling may be present in the delete d region of chromosome 10q25.1-25.3, Patients with a phenotype consistent w ith CLS, but lacking a family history suggestive of an X-linked disorder, s hould be evaluated with chromosome analysis paying particular attention to the region 10q25.(C) 2000 Wiley-Liss, Inc.