OBJECTIVE: To report on a child with B-cell-negative severe combined immunodeficiency (B-SCID) manifesting as fulminant myocarditis and carry out genetic testing for her. METHODS: A child with B-SCID who presented at Fujian Maternity and Child Health Care Hospital on January 31, 2021 was selected as the subject. Whole exome sequencing was carried out for her. Candidate variant was verified by Sanger sequencing. RESULTS: The female infant had developed recurrent skin and lung infections soon after birth, and was admitted due to fulminant myocarditis. Serological examination has disclosed a remarkable reduction in immunoglobulins. Flow cytometric analysis revealed that her peripheral blood T and B lymphocytes and NK cells were significantly reduced. Whole exome sequencing revealed that she has harbored a homozygous c.C3007T (p.Q1003X) nonsense variant of the RAG1 gene, for which both of her parents were heterozygous carriers. The variant has not been recorded in normal population databases. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic. CONCLUSION A case of RAG1 gene associated B-SCID has been diagnosed. Above finding has enriched the spectrum of RAG1 gene variants and enabled early diagnosis and intervention of the disease.
Female ; Humans ; Pregnancy ; Genetic Testing ; Homeodomain Proteins/genetics* ; Mutation ; Myocarditis/genetics* ; Phenotype ; Severe Combined Immunodeficiency/diagnosis* ; Infant

OBJECTIVEOmenn 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.

METHODOne 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.

RESULTThe 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.

CONCLUSIONOmenn 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.

Amino Acid Sequence ; Biomarkers ; blood ; DNA Mutational Analysis ; DNA-Binding Proteins ; genetics ; Genotype ; Homeodomain Proteins ; genetics ; Humans ; Infant ; Lymphocytes ; immunology ; pathology ; Male ; Microsatellite Repeats ; Mutation ; Nuclear Proteins ; genetics ; Phenotype ; Receptors, Antigen, T-Cell, alpha-beta ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Severe Combined Immunodeficiency ; diagnosis ; genetics ; pathology

X-linked severe combined immunodeficiency (X-SCID) is a rare, life-threatening immune disorder, caused by mutations in the gamma c chain gene, which encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. A 13-month-old boy with recurrent infections who had reduced serum immunoglobulin levels and decreased numbers of CD3, CD16/56 cells was evaluated for gamma c chain gene mutation and protein expression. The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP. The patient's mother was a heterozygous carrier. Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy. As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence. This is the first report of the molecular diagnosis of X-SCID in Korea. Genetic analysis of the gamma c chain gene is useful for definite diagnosis and genetic counseling for X-SCID.
Arginine/chemistry ; Cysteine/chemistry ; DNA/metabolism ; DNA Mutational Analysis ; Female ; Flow Cytometry ; Genetic Counseling/*methods ; Heterozygote ; Human ; Immunoglobulins/metabolism ; Immunophenotyping/methods ; Korea ; *Linkage (Genetics) ; Male ; *Mutation ; Pedigree ; Point Mutation ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Receptors, Immunologic/*genetics ; Sequence Analysis, DNA ; Severe Combined Immunodeficiency/*diagnosis/*genetics ; Support, Non-U.S. Gov't ; Time Factors ; *X Chromosome