Table 1.

Gene and Chromosomal localization

Condition	Gene	Chromosome	Comments	Clinical
X-linked CGD	CYBB	XP21	Deletion or missense, nonsense and/or frameshift mutations may occur	Opportunistic infection Autoimmunity Organ dysfunction
McLeod syndrome	XK	XP21	Absent Kx antigen and weak expression of Kell on RBC surface XK is linked to Kell blood group antigen Kell locus mutations can also lead to the syndrome	Acanthocytosis Elevated CPK Huntington's chorea-like disease Muscle weakness and atrophy Cardiomyopathy Psychiatric disease Cognitive impairment