FAMILIAL TRANSLOCATION T(10,14)(Q26.1,Q32.3) - REPORT OF 3 OFFSPRING WITH 10Q-DELETION AND 14Q-DUPLICATION

We describe two brothers and a cousin with common clinical features, i ncluding mild mental retardation, motor delays, hypotonia with truncal ataxia, esotropia, and mild facial and hand dysmorphia, The initial r outine chromosome study failed to detect any abnormality in the proban d. Based on a high index of clinical suspicion, high-resolution chromo some studies were performed on the proband's parents. A small reciproc al translocation t(10;14) (q26.1;q32.3) was detected in the father. Th e breakpoint on the derivative chromosome 14 was further placed telome ric to the immunoglobulin heavy-chain gene cluster at the band q32.33 by fluorescence in situ hybridization. Studies of the proband and two affected paternal cousins revealed that each had inherited the same de rivative chromosome 10 from their carrier parents. This unbalanced kar yotype resulted from an adjacent-1 segregation of the 10;14 translocat ion.