Mutations in the gene for the common gamma chain (gamma(c)) in X-linked severe combined immunodeficiency

X-linked severe combined immunodeficiency (XSCLD) consitutes a disorder of the immune system caused by mutations in the gene encoding the common gamma chain (gamma(c)), a subunit of the IL-2, IL-4, IL-7, IL-9 and IL-15 recept ors, which are necessary for lymphocyte development and function. In this s tudy the IL2RG gene of 31 patients with severe combined immunodeficiency (S CID) was examined by nonradioactive single-strand conformation polymorphism and sequence analysis. Among the ii patients with XSCID, ten different mut ations were identified in the IL2RG gene, including eight novel mutations. Ninety percent of the mothers of the XSCID patients are carriers of the mut ated allele. One patient showed low numbers of B-cells, a striking deviatio n from the classical B-cell-positive and T-cell-phenotype.