目的　探讨不典型严重联合免疫缺陷病（SCID）的诊断和治疗。方法　回顾分析2012年9月－2017年6月证 实为IL2RG、JAK3和RAG1突变的7例不典型SCID患儿的临床资料。结果　7例患儿中，婴儿5例，幼儿及学龄期儿童各1 例； 6例为男性、 1例为女性。例2、 4、 6为经典SCID临床表型，例1、 3、 5、 7为不典型SCID临床表型，例6临床诊断Omenn 综合征。例2、 5为经典SCID免疫表型，例1、 3、 4、 6、 7为不典型SCID免疫表型，例1有母体嵌合。二代测序提示，例1为 复合杂合JAK3突变c.3097-1G>A/ c.946-950GCGGA>ACinsGGT；例2、 3、 4为IL2RG突变，分别为c. 865C>T/p.R289X、 c.664C>T/R222C、52delG；例5为杂合JAK3突变c.2150A>G/p.E717G、c.1915-2A>G。Sanger测序提示，例6为复合杂合 的RAG1突变 c.994C>T/p.R332X、c.1439G>A/p.S480N；例7为纯合的RAG1突变 c.2095C>T/p.R699W。结论　SCID基 因突变在一定情况下可导致不典型的临床和/或免疫表现。

　Objective　To explore the diagnosis and treatment of atypical severe combined immunodeficiency disease (SCID). Methods　The clinical data of atypical SCID in 7 children with IL2RG, JAK3, and RAG1 mutations were reviewed and analyzed from September 2012 to June 2017. Results　In 7 cases (6 males and 1 female), there were 5 infants, 1 toddler and 1 school-age child. Cases 2, 4, and 6 were classic SCID clinical phenotypes. Cases 1, 3, 5, 7 were atypical SCID clinical phenotypes. Case 6 were diagnosed with Omenn syndrome. Cases 2, 5 were classic SCID immune phenotypes, cases 1, 3, 4, 6, 7 were atypical SCID immune phenotypes, and case 1 had maternal chimera. The next generation sequencing indicated that case 1 had a compound heterozygous JAK3 mutation with c.3097-1G>A/ c.946-950GCGGA>ACinsGGT. Cases 2, 3, and 4 had IL2RG mutations, with c. 865C>T/ p.R289X, c.664C>T/R222C, 52delG, respectively. Case 5 had JAK3 mutations with c.2150A>G/p.E717G and c.1915-2A>G. Sanger sequencing indicated that case 6 had a RAG1 mutation of complex heterozygosity with c.994C>T/p.R332X and c.1439G>A/p.S480N. Case 7 had homozygous RAG1 mutation with c.2095C>T/p.R699W. Conclusion　Under certain conditions, gene mutation can lead to atypical clinical and/or immune phenotypic SCID.