Clinical And Immunological Characteristics, Mutation Analysis Of Two Patients With Omenn Syndrome

objective Omenn syndrome(OS) is a rare autosomal recessive geneticdisorder, one of severe combined immunodeficiency disease. At present, OShas been found to be caused by mutations in RAG1or RAG2gene that resultin partial V(D)J recombination activity. This study is to describe clinical andimmunological features and identify posiible mutations of RAG1/2genes.All these data may be in favor of improving the understangding of thisdisease, eventually reducing the possibility of misdiagnosis and delayeddiagnosis.Methods Two patients with suspected SCID from hospitalized inChildren’s Hospital of Chongqing Medical University in2012were enrolled.Blood samples from patients and their parents were collectted for RAG1/RAG2gene amplification and sequencing, TCR Vβ analysis and TRECsquantitation.Results Both of the patients had typical clinical manifestations ofOmenn syndrome and T+B-NK+phenotype. Mutation analysis revealedcompound heterozygosity mutations in RAG1gene in both of the pateits. One novel mutation (3073insA,G1025L) was identified, the other threemutations (1180C>T,A394T;1806T>G,C602T;1949A>G,A650S) had beenreported previously. Most of the24TCR Vβ subfamilies presentedmonoclonal or oligoclonal peaks in case1. TRECs content of patients weremuch lower than that those of normal control.Conclusion We add information of clinical and immunologicalfeatures of Omenn syndrome in Chinese population. One of the fourmutation (3073insA,G1025L) is novel. The most effective treatment forOmenn syndrome patients is Hematopoietic stemcell transplantation, earlydiagnosis and timely stem cell transplantation may reduce mortality.