A female X-linked chronic granulomatous disease caused by Xchromosome inactivation

WANG Shiyu; JIANG Liping; ZHAO Xiaodong

doi:10.13431/j.cnki.immunol.j.20190062

Abstract：To enrich the understanding of X-linked chronic granulomatous disease (X-CGD) and to warn the prenatal diagnosis, the clinical data and CYBB gene characteristics of a rare female infant X-CGD patient were reported analyzed before and after birth. Flow cytometry was used to detect the respiratory burst function and gp91 phox expression of neutrophils in patient and her parents. The CYBB gene was analyzed by direct sequencing.After restriction enzyme digestion of DNA, X chromosome inactivation was calculated by detecting fluorescent PCR products with capillary electrophoresis. The female patient's twin brothers were X-CGD patients, and their motherwas a carrier of mutant gene. DNA analysis of amniotic fluid cells showed the patient is a carrier of CYBB gene exon 9 c. 1123 delG heterozygous mutation. At the age of 2 months, she had perianal abscess as her first symptom. Respiratory burst function of neutrophils in peripheral blood of the patient was abnormal (SI= 0.65, NBT=0％), and no gp91 phox protein was expressed. The c DNA sequencing revealed a homozygous mutation of CYBB exon 9 c.1123 delG in the patient; the X chromosome inactivation rate was 99.5％ in the patient and 76.1％ in her mother. Taken together, for the possibility of healthy X chromosome inactivation in female carriers, the DNA and Cdna of the fetus should be analyzed during prenatal diagnosis. For female CYBB heterozygous mutant fetuses, the respiratory burst function of neutrophils in cord blood should be examined to determine whether they are female patients.