Oligonucleotide ligation assay combined with polymerase chain reaction (PCR-OLA) is a technique which can be used for the detection of characterized sequence variations. In the present study, new PCR-OLA methods were developed for the detection of the major mutations causing infantile neuronal ceroid lipofuscinosis (INCLFin), congenital nephrotic syndrome of Finnish type (NPHS1 FinMajor and FinMinor) and medium chain acyl-CoA dehydrogenase deficiency (MCAD A985G). The prevalence of these mutations in the Finnish population was studied by analyzing blood samples collected in eastern Finland. The throughput of PCR-OLA was further enhanced by optimizing the direct use of dried blood spot (DBS) specimens for PCR. This study demonstrated that PCR-OLA is an accurate method for the detection of gene defects causing inherited disorders. With automation, PCR-OLA can be applied for routine diagnosis and for carrier screening from a large number of specimens.