Characterization of the gamma c chain among 27 unrelated Japanese patientswith X-linked severe combined immunodeficiency (X-SCID)

X-linked severe combined immunodeficiency (X-SCID) is a rare fatal disease that is caused by mutations in the gene encoding the ye chain. In this stud y, 27 unrelated Japanese patients with X-SCID were examined in terms of the ir genetic mutations and surface expression of the ye chain. Among 25 patie nts examined, excluding two patients with lar ge deletions, 23 different mu tations were identified in the IL2RG gene, including 10 novel mutations. On e patient bearing an extracellular mutation and all three of the patients b earing intracellular mutations after exon 7 expressed the ye chain on the c ell surface. Overall, 84% of patients lacked surface expression of the gamm ac chain leading to a diagnosis of X-SCID.