Deletion of the OPHN1 gene detected by aCGH.

Background The oligophrenin 1 gene ( OPHN1) is an Rho-GTPase-activating protein involved in the regulation of the G-protein cycle required for dendritic spine morphogenesis. Mutations in this gene are implicated in X-linked mental retardation (XLMR). Methods We report a deletion spanning exons 21 and 22 of the OPHN1 gene identified by a tiling path X-chromosome array comparative genomic hybridization (CGH) and multiplex ligation-dependent probe amplification, confirmed by polymerase chain reaction (PCR), in a family with four males with intellectual disabilities. Results Patients harbouring mutations in this gene share the same clinical manifestations reinforcing the idea of a syndromic XLMR. The most important neurological findings are cerebellar hypoplasia and ventriculomegaly. Conclusions We recommend screening of the OPHN1 gene in male patients with XLMR and cerebellar anomalies. This case highlights the value of high-resolution techniques as Multiplex Ligation Probe Amplification (MLPA) and CGH array for a better characterization of copy number changes and suggests that MLPA technology may be very useful for an initial screening of small deletions and duplications in XLMR patients. [ABSTRACT FROM AUTHOR]