A de novo 1.13 Mb microdeletion in 12q13.13 associated with congenital distal arthrogryposis, intellectual disability and mild dysmorphism.

A girl presented with congenital arthrogryposis, intellectual disability and mild bone-related dysmorphism. Molecular workup including the NimbleGen Human CGH 2.1M platform revealed a 1.13 Mb de novo microdeletion on chromosome 12q13.13 of paternal origin. The deletion contains 33 genes, including AAAS, AMRH2, and RARG genes as well as the HOXC gene cluster. At least one gene, CSAD, is expressed in fetal brain. The deletion partially overlaps number of reported benign CNVs and pathogenic duplications. This case appears to represent a previously unknown microdeletion syndrome and possibly the first description in humans of a disease phenotype associated with copy loss of HOXC genes.