[DNA analysis of cytochrome b positive chronic granulomatous disease (a case report)]

A patient was diagnosed as having chronic granulomatous disease (CGD). This case seems to have been transmitted in an X-linked from judging from the family history. We had previously suggested that the patient's cytochrome b was normal both qualitatively and quantitatively. Thus, we thought that there might be mutation in the gp91-phox (one of the two components of cytochrome b) gene affecting electron transport but leaving other functions intact. To confirm this speculation, we performed DNA analysis. Complementary DNA (cDNA) was obtained from messenger RNA (mRNA) derived from peripheral blood lymphocytes. By using primers specific for the gp91-phox cDNA, the cDNA was amplified by polymerase chain reaction (PCR). The amplified cDNA was then ligated into Blue Script vector and transfected into E. coli (JM109) in order to clone the cDNA of gp91-phox. Then, the cloned cDNA was sequenced. Sequence analysis showed that the nucleotides 1521-1525 were deleted and a new sequence of 8 nucleotides was substituted. This mutation converted Glu-Lys-Thr into His-Ile-Trp-Ala. To confirm that the mutated allele came from the patient's mother; we performed mismatched PCR. PCR using a mutated allele could produce approximately 250 base pair products only when the patient's cDNA was used. PCR using a wild type primer could produce 250 base pair products only when cDNA from a healthy donor was used.(ABSTRACT TRUNCATED AT 250 WORDS)