Interstitial deletion 2p11.2-p12: report of a patient with mental retardation and review of the literature.

Deletions of chromosome bands 2p11.2 and 2p12 are rare, and only six patients have been reported to date. Here, we report on a 5-year-old girl with an 11.4 Mb interstitial deletion of chromosome bands 2p11.2-p12 and the characterization of this deletion by high-resolution array CGH. The patient presented with mental retardation, microcephaly and short stature. Facial features included broad nasal bridge, frontal bossing and mild dolichocephaly. Phenotypic comparison with previously published patients failed to reveal a consistent clinical pattern apart from developmental delay/mental retardation, which is probably due to different sizes and/or positions of the individual deletions. Among the 40 known genes deleted in our patient is REEP1, haploinsufficiency of which causes autosomal dominant spastic paraplegia type 31 (SPG31, OMIM 610250). Additional patients with well-characterized deletions within 2p11.2 and 2p12 will be needed to determine the role of individual genes for the clinical manifestations.