Development of a multiplex ligation-dependent probe amplification (MLPA) assay for quantification of the OCRL1 gene

Objectives To develop and evaluate the efficacy of Multiplex Ligation-dependent Probe Amplification (MLPA) technique in detection of genomic rearrangements of the OCRL1 gene associated with Oculocerebrorenal syndrome of Lowe (OCRL). Design and methods Four synthetic MLPA probe sets have been designed to measure exons copy number in OCRL1 gene. After OCRL1 MLPA probe sets validation in 7 OCRL1 deleted patients, we screened 5 female patients to asses their carrier status and 15 patients with suspected OCRL, previously diagnosed as sequence-negative. Results MLPA was able to detect all the known deletions. Two of five females were detected as carrier for the family mutation. Neither mosaic deletion nor duplication was found in the 15 patients suspected of having Lowe syndrome. Conclusions Our MLPA allows rapid and precise OCRL1 gene quantification. Moreover this study provides no further evidence for the hypothesis that duplications and deletion somatic mosaic deletions account for the fraction of patients who have no detectible mutation after the usual screening procedures.