Characterization of CTNS mutations in Arab patients with Cystinosis

Background: Cystinosis is an autosomal recessive disease characterized by impaired transport of free cystine out of lysosomes with resulting renal and ophthalmic manifestations. Mutations in CTNS, encoding cystinosin, are the only known cause of this autosomal recessive disorder with more than 85 different mutations described so far. Purpose: To identify CTNS mutations in Arab cystinosis patients. Methods: In this study, we have analyzed the mutational spectrum of CTNS in a population of 21 patients from 13 families of Arab origin. The entire coding region and flanking intronic regions of CTNS were analyzed by direct sequencing. Results: Eight mutations were identified, four of which are novel (c. 530A>G, c. 681G>A, 1013T>G, and c. 1018_1041del). Conclusion: These alleles will provide the basis for routine molecular diagnosis of cystinosis in the region.