A novel interstitial deletion in Xq25, identified by array-CGH in a patient with Lowe syndrome

The oculocerebrorenal syndrome of Lowe (OCRL) (MIM:309000) is an X-linked multisystemic disorder affecting the eyes, nervous system and kidneys due to mutations in OCRL1 gene. The gene contains 24 exons, and encodes a 105 kDa phosphatydylinositol 4,5-biphosphate [PtdIns(4,5)P2] 5-phosphatase localized primarily in the trans-Golgi network and the lysosomes. The large majority of the OCRL1 mutations producing Lowe syndrome are either missense mutations localized mainly in the catalytic domain or non-sense/frameshift mutations resulting in truncated proteins. Rarely, in about 6% of the cases, the disease results from large gene deletions occurring in the 5′ part of the gene. Here we report a new case of a patient with Lowe syndrome due to a deletion of about 4 Mb, encompassing the OCRL1 gene, detected by PCR and CGH array. The mother was carrier of the same deletion.