Partial trisomy 1q (1q42.13-->qter) and partial monosomy 6q (6q27-->qter) in a girl with single median maxillary central incisor, corpus callosum dysgenesis and developmental delay.

A 3-year-old girl presented with mental retardation, developmental delay, seizures, hypotonia, brachycephaly, a triangular face, single median maxillary central incisor (SMMCI), prominent forehead, down-slanting palpebral fissures, hypertelorism, a high-arched palate, micrognathia and low-set ears. Computed tomographic scans revealed corpus callosum dysgenesis and hypoplasia of bilateral frontal sinuses. Oligonucleotide-based array comparative genomic hybridization analysis revealed a -20.7-Mb duplication of 1q42.13-->qter and a -3.6-Mb deletion of 6q27-->qter. The karyotype of the girl was 46,XX,der(6)t(1;6)(q42.13;q27)pat. Mutational analysis of the patient revealed no mutation in the genes of SHH, SIX3 and TGIF. The present case adds unbalanced chromosome aberration of partial trisomy 1q and partial monosomy 6q to the list of genetic conditions associated with SMMCI.