The first molecular genetics analysis of individuals suffering from nephropatic cystinosis in the Southwestern Iran.

Objective: Nephropatic Cystinosis (NC) is a rare metabolic disorder due to mutation in the CTNS gene in which more than 90 different mutations have already been reported so far. This study was performed to investigate mutations of the CTNS gene and its promoter in a number of Iranian patients with NC.

Methods: Polymerase chain reaction and direct sequencing were performed for molecular characterization of the CTNS gene in 25 patients from 24 unrelated Iranian families with NC.

Results: None of the patients showed the 57 kb deletion in heterozygous or homozygous manner. One was homozygous for a novel mutation, which was termed as "c.153-155insCT", while one of the cases was homozygous and another was compound heterozygous for the second novel mutation c.923G>A. Moreover three known mutations c.18-21delGACT, c.1017G>A, and c.681G>A in 11 of the patients were detected. No apparent mutation was observed in the rest of patients (44%, n=11).

Conclusion: The present data exhibit a fundament for molecular carrier detection and prenatal diagnosis of a relatively large percentage of Iranian patients suffering from NC, at least in the Southwestern Iran, where Arab ethnicity is one of the common ethnicities of the region.