Prenatal diagnosis of RAG-deficient Omenn syndrome

Mutations in recombination activating genes (Rplc) 1 and 2 have been found to cause Omenn syndrome (OS), a severe combined immunodeficiency (SCID) wit h a peculiar phenotype. Here we report the prenatal diagnosis performed in three Of patients, Mutations were detected in the probands as well as in th eir parents lay genomic sequencing of the complete coding regions of both R AG 1 and RAG 2, which are contained in a single exon. All the three proband s had RAG 1 mutations in both alleles, at least one of which was a missense substitution. Of the three fetuses tested, one had a wild type sequence on both alleles, while the other two had one mutated allele. None of the thre e patients were predicted to be affected and this was confirmed ar birth. D etection of RAG genes mutations on fetal samples by direct sequencing is an easy and effective way to investigate fetuses from families affected with RAG-dependent SCID and OS families affected by RAG-dependent SCID and OS. C opyright (C) 2000 John Wiley % Sons, Ltd.