Detection of the three common mutations of adeninephosphoribosyltransferase deficiency among Japanese.
We analyzed DNA from six Japanese patients with adenine phosphoribosyltransferase (APRT) deficiency who developed 2,8-dihydroxyadenine (DHA) urolithiasis. These six patients were selected for DNA analysis since they were expected to possess allele(s) with mutations other than two known abnormalities, i.e. a missense mutation at codon 136 (APRT*J allele) and a nonsense mutation at codon 98. In three of the six patients an insert of four bases CCGA was detected in exon 3 by sequencing clones obtained from the genomic DNA. In two of the three patients, both of the two alleles had this mutation (homozygotes) while the other patient had the APRT*J allele in addition to the allele with the 4-base insertion. To search for mutations other than the above three defined germline mutations, we amplified a genomic DNA segment including all the 5 exons of the APRT gene by PCR and cloned it into a plasmid. After selecting recombinant plasmids containing neither of the three defined mutations, we sequenced the entire APRT exons and introns. Abnormalities were found in neither the coding regions nor the exon-intron junctions. Disease-related mutations in these mutant alleles may exist in either 5' or 3' flanking sequences and remain to be elucidated.
Higashimoto
H
H
Center for Molecular Biology and Cytogenetics, Tokyo, Japan.
Ouchi
A
A
Kawaguchi
R
R
D000228:Adenine Phosphoribosyltransferase / Q000172:deficiency* / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000302:isolation & purification; D004252:DNA Mutational Analysis; D005091:Exons; D005838:Genotype; D018095:Germ-Line Mutation; D006801:Humans; D007564:Japan; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction
D004247:DNA; D000228:Adenine Phosphoribosyltransferase