De novo 46,XX, dir dup (11)(q133.3-->q14.2) in a patient with mental retardation, congenital cardiopathy and thrombopenia.

A 31-year-old female is reported with mild to moderate mental retardation, facial dysmorphy, congenital cardiopathy, and mild thrombocytopenia as the most important clinical findings. Chromosome analysis in lymphocytes showed a de novo dir dup (11)(q13.3-->14.2), by both G-banding and FISH techniques. Previously reported constitutional duplications of 11q are mostly the result of unbalanced translocations involving chromosome 11q, and are associated with a partial monosomy or trisomy of the translocation partner chromosome. In case of an unbalanced translocation it is not clear which clinical findings result from the chromosome 11 duplication and which result from the abnormality on the translocation partner chromosome. This is the first report on a constitutional duplication of chromosome region 11q13.3-->14.2 without involvement of other chromosomes.