[Determination of gene mutation of silent serum cholinesterase and its epidemiologic characters in the Japanese].

We detected 121 individuals with silent type of serum cholinesterase from 36 families in Japan. DNA analysis totaling 37 members of eleven blood unrelated families were carried out by four useful methods, namely, 1) PCR-SSCP analysis, 2) dot blot hybridization (DBH) with the use of synthetic oligonucleotide probe, 3) restriction endonuclease analysis (REA) and 4) direct sequencing analysis. Their mutations were classified into four groups, namely, 1) a G-->C transversion at codon 365, 2) a frameshift mutation with insertion of an extra A at codon 315, 3) an A-->G transition at codon 128 and 4) a C-->A transition at codon 400. The three procedures including (PCR-SSCP, DBH, REA) without the use of radio labeled materials (non-RI) are recommendable for the analyses. However, the direct sequencing analysis of bases with RI might be, at present, necessary for the final identification.