Familial mental retardation associated with balanced chromosome rearrangement rcp t(8;11)(q24.3;p15.1).

We report three sisters and their father with a reciprocal balanced translocation, rcp t(8;11)(q24.3;p15.1) and the same abnormal phenotypes, including mental retardation, growth disturbance, and amblyopia. It is considered that the abnormal phenotypes in our four cases might result from a tiny deletion or gene mutation at the breakpoints in 8q or 11p or both. Our cases showed no resemblance, apart from mental retardation, to Langer-Giedion syndrome, which is caused by the deletion of 8q23.3 and 8q24. Furthermore, our patients did not have the cardinal features of Beckwith-Wiedermann syndrome or WAGR which are caused by deletion of 11p. It is suggested that the amblyopia in our four cases might have resulted from the breakpoints at 11p15.1.