Application of polymerase chain reaction-single strand conformation polymorphism analysis to the diagnosis and screening of adenine phosphoribosyltransferase deficiency

Summary

Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis is a rapid and sensitive method used to identify point mutations in a given sequence of genomic DNA. We applied this method to the diagnosis of adenine phosphoribosyltransferase (APRT) deficiency, which is an autosomal recessive hereditary disease leading to 2,8-dihydroxyadenine urolithiasis. Genomic APRT genes were amplified and labeled simultaneously with [α^-32P]dCTP (cytidine triphosphate) by PCR. When run in a 6% polyacrylamide gel containing 10% glycerol, two types of mutant genes-APRT^*QO and APRT^*J-gave bands clearly distinct from those of the equivalent normal APRT genes. Using this method we diagnosed both homozygotes and heterozygotes for defective APRT genes. On screening 80 Japanese individuals for polymorphism or mutations by PCR-SSCP we did not find any alterations leading to a false positive diagnosis. These findings suggest that PCR-SSCP, in addition to being rapid and sensitive, is a useful diagnostic method which is highly specific in detecting mutant APRT genes in the Japanese population.