Genetic analysis of CYBB gene in 26 korean families with X-linked chronic granulomatous disease

Abstract

Chronic granulomatous disease (CGD) is a rare hereditary disorder that is characterized by a greatly increased susceptibility to life-threatening bacterial and fungal infections. CGD is caused by mutations in any one of the genes encoding subunits of phagocyte NADPH oxidase. X-linked CGD, more than half of all CGD cases, is caused by mutations in CYBB gene encoding gp91-phox subunit. We identified the mutations in the CYBB gene of 29 Korean patients with X-linked CGD from 26 unrelated families. Twenty-three mutations were identified: five splice site mutations (c.45 + 1G > C, c.141 + 5G > A, c.897 + 2T > C c.1461 + 1G > T, c.1586 + 2T > A), four frameshift mutations (c.27dupG, [c.737A > C; c.742delA], c.742dupA, c.1636 del C), seven non-sense mutations (c217C > T, c.469C > T, c.676C > T, c.868C > T, c.1222G > T, c.1272G > A, c.1281T > A), five missense mutations (c.164 C > A, c.422T > C, c.665 A > G, c.1012C > T, c.1461G > T) and two gross deletions. Eight out of 23 mutations identified in this study are novel mutations: two splice mutations(c.897 + 2T > C, c.1586 + 2T > A), two frame shift mutations ([c.737A > C; c.742delA], c.1636 del C), two nonsense mutations (c.1222G > T, c.1281T > A), one missense mutation (c.1461G > T), one gross deletion (c.1667_1629 del.). Our results confirmed that mutations of CYBB gene in the X-CGD are very heterogeneous and not show the peculiarity of the ethnic group.

Keywords: CYBB gene; NADPH oxidase; X-linked CGD; gp91-phox.