Familial robertsonian 13;14 translocation with mental retardation and epilepsy.

Familial reports of a robertsonian translocation in more than two generations are rare. We report three generations (a daughter, the mother, and the mother's father) with a heterozygous, balanced robertsonian translocation t(13;14)(q11;q11). Central nervous system disease was present, but differentially expressed, in generations I and III. The daughter presented with mental delay and epilepsy, and the mother was apparently healthy, whereas the mother's father was again symptomatic, with borderline intelligence. Fluorescent in situ hybridization analysis was performed to exclude a loss or gain of chromosomal material. No uniparental disomy was present. We concluded that genetic counseling in the presence of this rearrangement was extremely difficult, independent of the affected parent being symptomatic or asymptomatic.