Development of a universal chemiluminometric genotyping method for high-throughput detection of 7 LDLR gene mutations...

Familial hypercholesterolemia (FH) is caused by mutations in the LDL receptor (LDLR) gene. We report the application of a universal method with high allele discrimination properties to the simultaneous genotyping of 7 LDLR mutations in Greeks, in dry-reagent format.

We genotyped mutations C858A, C939A, G1285A, T1352C, G1646A, G1775A, C/T81G. Unpurified amplicons from a multiplex PCR that produced fragments encompassing all 7 mutations were subjected to probe extension reactions in the presence of fluorescein-modified dCTP, and a microtiter well-based assay of extension products with a peroxidase-antifluorescein conjugate and a chemiluminogenic substrate. We used lyophilized dry reagents and assigned genotypes by the signal ratio of normal-to-mutant-specific probe.

We standardized the method and optimised all steps for specificity. The method was validated by genotyping blindly 119 (833 genotypings). Results were fully concordant with other methods used as standards.

This method is accurate, simple, rapid and robust. The microtiter well format allows genotyping of a large number of samples in parallel for several mutations.