The most prevalent type was IL2RG-SCID (n = 10; 19 % of typical SCID cases), followed by IL7R-SCID (n = 6; 11 %), SCID of unknown etiology (n = 6; 11 %), ADA-SCID (n = 5; 9 %), RAG1-SCID (n = 5; 9 %), JAK3-SCID (n = 3; 6 %). This evidence concerns the gene IL2RG and severe combined immunodeficiency.