title: [Clinical phenotype and gene diagnostic analysis of Omenn syndrome].
abstract: OBJECTIVE
  Omenn syndrome is a rare autosomal recessive hereditary severe combined immunodeficiency. The purpose of this study was to understand clinical characteristics and genetic mutation type of Omenn syndrome and to improve the recognition of Omenn syndrome among pediatric clinicians.
  
  
  METHODS
  One suspected case of severe combined immunodeficiency was found to have pneumonia repeatedly, intractable diarrhea, poor antibiotic treatment effect, lymphadenopathy, hepatosplenomegaly and erythroderma. The patient was diagnosed as having Omenn syndrome by RT-PCR, and the expression of RAG1/RAG2 and gene analysis of RAG1/RAG2 were performed.
  
  
  RESULTS
  The classification of lymphocyte was CD3(+) cells (35.3%), CD19(+) cells (0.4%), CD16(+) cells (57.6%). After stimulation with phytohemagglutinin (PHA), lymphocyte proliferation of the child was extremely low. Genetic studies showed RAG1 homozygous deletion mutation (2302 del T). He had detectable activated T-lymphocytes with low circulating B-lymphocytes and no evidence of maternal T-cell engrafment as indicated by the short tandem repeat (STR) analysis.
  
  
  CONCLUSIONS
  Omenn syndrome is a severe combined immunodeficiency disease caused by mutations in the RAG1/RAG2 gene. The disease has been reported rarely in China. The clinical manifestations of the disease is early postnatal repeated infections and erythroderma. Mutation analysis of RAG1/RAG2 gene may help to confirm the diagnosis and may be useful in early immune reconstitution and genetic counseling.
authors.affiliation: Department of Pediatrics, Guizhou Province People's Hospital, Guiyang, China.
authors.forename: Yan-qiong
authors.initials: YQ
authors.lastname: Wang
authors.forename: Yu-xia
authors.initials: YX
authors.lastname: Cui
authors.forename: Jie
authors.initials: J
authors.lastname: Feng
mesh_terms: D000595:Amino Acid Sequence; D015415:Biomarkers / Q000097:blood; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics*; D005838:Genotype; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007223:Infant; D008214:Lymphocytes / Q000276:immunology / Q000473:pathology; D008297:Male; D018895:Microsatellite Repeats; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics*; D010641:Phenotype; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016511:Severe Combined Immunodeficiency / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology
chemical_list: D015415:Biomarkers; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; C499311:RAG2 protein, human; D016693:Receptors, Antigen, T-Cell, alpha-beta; C064658:RAG-1 protein