Unbalanced translocation der(8)t(8:13)(p23.3;q32.1)dn identified by array CGH and subtelomeric FISH in a patient with mental retardation

Molecular cytogenetics allows the identification of unknown chromosome rearrangements, which is clinically useful in patients with mental retardation and/or development delay. We report on a 31-year- old woman with severe mental retardation, behavior development delay, and verbal performance delay. Conventional cytogenetic analysis showed a 46,XX,add(8)(p23.3) karyotype. To determine the origin of this unbalanced translocation, we performed array CGH and subtelomeric FISH. The results showed that the distal region of chromosome 8p was added to the terminal of chromosome 13q. This was confirmed the final result of 46,XX,der(8)t(8:13)(p23.3;q32.1)dn.