Subtelomeric 6p monosomy and 12q trisomy in a patient with a 46,XX,der(6)t(6;12)(p25.3;q24.31) karyotype: Phenotypic overlap with Mutchinick syndrome.

We report on a patient with partial monosomy 6p and partial trisomy 12q identified by fluorescent in situ hybridization (FISH) and array-based comparative genomic hybridization (aCGH). She had a complex phenotype characterized by mental retardation (MR), psychomotor developmental delay, speech disorder, hypertelorism, eye anomalies, hearing loss, low-set malformed ears, thin upper lip, heart defect, clinodactyly, pes valgus, and skeletal anomalies. There is phenotypic overlap between our case and Mutchinick syndrome. This is the first report of a combined partial monosomy 6p and partial trisomy 12q due to an unbalanced translocation between subtelomeric regions of these chromosomes.