Abstract
Purpose: :
To determine the frequency of the most common reported disease causing mutations in Leber congenital amaurosis (LCA) patients from southern India.
Methods: :
A cohort of 51 LCA families and 25 controls from southern India were tested for the 70 most common disease-causing mutations that have been previously detected in patients from North America. The 70 mutations are distributed across 7 genes (AIPL1, CRB1, CRX, GUCY2D, RDH13, RPE65, RPGRIP and NPHP6). Subjects were tested for 69 of the mutations using a customized SNPlex assay (ABI, Inc), and for the Intron 26 1655 A>G mutation in NPHP6 (CEP290) with bi-directional sequencing. Mutations detected by SNPlex were confirmed with bi-directional sequencing.
Results: :
A homozygous Tyr368His TAT>CAT mutation in RPE65 was identified in one family using SNPlex and confirmed by bi-directional sequencing. No other instances of mutations common in the North American population were detected in the Indian LCA or control samples including the NPHP6 (CEP290) intron 26 1655 A>G mutation which accounts for one third of LCA in America.
Conclusions: :
In 2007, 70% of LCA in patients from North American have disease attributed to mutations in one of 11 genes. However, only one instance of the disease-causing mutations that are common among North American patients was detected among the 51 LCA families from south India. LCA in India appears to be caused by a different spectrum of mutations (in known and unknown genes).
Keywords: genetics • gene screening • gene mapping