Genetic heterogeneity in patients with X-linked recessive chronic granulomatous disease

Genetic heterogeneity in 12 patients from 11 different families with X-linked recessive chronic granulomatous disease was studied by Southern blot analysis using cytochrome b heavy-chain cDNA as a probe. We found the abnormal restriction length fragment patterns of the cytochrome b heavy-chain gene in three families, which were not observed in healthy controls. DNA from one patient showed the abnormal patterns after digestion with several restriction enzymes. The DNA of two other patients showed the abnormality only with TaqI and PstI. Analysis of the same family members indicated that these abnormal patterns cosegregated with the disease. The other nine patients from eight families did not have any abnormalities detectable by Southern blot analysis. Although further experimentation should be done to study the molecular genetic heterogeneity in most X-linked chronic granulomatous disease families (eight of 11), we were able to demonstrate at least three different types of mutations in the cytochrome b heavy-chain gene responsible for the disease.