Identification of two novel mutations in the OCRL1 gene in two Chinese families with Lowe syndrome.

AIM: Lowe syndrome is a rare, multisystem, X-linked disorder characterized by anomalies affecting the eyes, the nervous system and the kidneys. The objective of this study was to identify and characterize the clinical manifestations of mutations of the causative gene in two Chinese families with Lowe syndrome.

METHODS: Lowe syndrome was diagnosed based on the clinical manifestations and laboratory and imaging findings. Altogether, 164 DNA samples, including samples from three affected subjects, five family members (from two families) and 156 healthy donors, were analyzed to identify the mutations in the OCRL1 gene.

RESULTS: In family 1, proband 1 had a novel nonsense mutation (c.880G>T) in exon 10 of the OCRL1. This mutation led to a premature termination of the OCRL1 protein (p.Glu294X). In family 2, a novel insertion mutation (c.2626dupA) in exon 24 of OCRL1 was found in proband 2 and his affected elder brother. This mutation likely results in the degradation of the OCRL1 protein (p.Met876AsnfsX8). Both probands' mothers were identified as carriers of the respective mutations. These mutations were not found in the unrelated controls.

CONCLUSIONS: Our study suggests that the novel nonsense mutation (c.880G>T) in exon 10 and the novel insertion mutation (c.2626dupA) in exon 24 of the OCRL1 gene cause Lowe syndrome in these two Chinese families.