SCREENING FOR MUTATIONS CAUSING X-LINKED SEVERE COMBINED IMMUNODEFICIENCY IN THE IL-2R-GAMMA CHAIN GENE BY SINGLE-STRAND CONFORMATION POLYMORPHISM ANALYSIS

Mutations in the common gamma chain (gamma(c) or IL2RG) of the interle ukin-2, -4, -7, -9 and -15 receptors have been found to cause X-linked severe combined immunodeficiency (SCIDX1). We report here on the muta tions identified in a further ten families. Two of the mutations ident ified have occurred twice in unrelated families, indicating two possib le mutational hotspots. Seven of the mutations, which were identified by single-strand conformational polymorphism (SSCP) analysis, are poin t mutations, and the eighth is a small deletion. We also report on the first use of assays based on these mutations within IL2RG for unambig uous carrier determination. The consequences for the gamma(c) proteins produced as a result of these mutations are discussed.