A single nucleotide base transition is the basis of the common human glucose-6-phosphate dehydrogenase variant A (+).
The X-chromosome-linked glucose-6-phosphate dehydrogenase (G6PD) A(+) is a common variant found in about 20% of blacks. The amino acid substitution of Asp in the variant G6PD A(+) for Asn in the normal G6PD B(+) was previously found (A. Yoshida, 1967, Proc. Natl. Acad. Sci. USA 57: 835), but the exact substitution position has not been identified. By screening a DNA library prepared from genomic DNA of a G6PD A(+) male subject, we obtained a genomic clone that contained the mutation site. Characterization of the clone revealed that AT----GC transition occurred in the variant A(+) gene, thus producing the amino acid substitution Asn----Asp at the 142nd position from the NH2 terminus of the enzyme. The nucleotide change created an additional FokI cleavage site in the variant A(+) gene; thus, the FokI fragment type of the variant subjects differed from that of normal B(+) subjects in Southern blot hybridization analysis.
Takizawa
T
T
Department of Biochemical Genetics, Beckman Research Institute of the City of Hope, Duarte, California 91010.
Yoneyama
Y
Y
Miwa
S
S
Yoshida
A
A
D000595:Amino Acid Sequence; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D008040:Genetic Linkage; D014644:Genetic Variation; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D014960:X Chromosome
D004247:DNA; D005954:Glucosephosphate Dehydrogenase