Familial t(1;17)(p34;q25) Balanced Translocation Carrier with Mental Retardation and Epilepsy Cases: Scientific Letter

Abstract

Reciprocal translocations, the most frequent structural aberration in humans, are mainly transmitted by one of the parents. Balanced reciprocal translocations occur at a frequency of approximately I in 600 live births. Familial reciprocal translocations are generally without phenotypic effect, although there is some evidence for a small excess of mental retardation (MR) in children carrying familial reciprocal translocations. We describe three children presenting with moderate MR/epilepsy and a familial balanced reciprocal translocation inherited from the mother. Cytogenetic analysis of peripheral blood lymphocytes showed a balanced reciprocal translocation t(1;17)(p34;q25) in all 25 analyzed metaphase spreads. Some of the apparently balanced rearrangements associated with MR may be unbalanced at the molecular level. Further detailed molecular analysis is required to characterize these breakpoints.