Inborn errors of immunity (IEI) are a diverse group of disorders caused by defects in immune system structure or function, involving both innate and adaptive immunity. The 2022 update of the IEI classification includes 485 distinct disorders, categorized into ten major disease groups. With the rapid development of molecular biology, the specific pathogenesis of many IEI has been revealed, making gene therapy possible in preclinical and clinical research of this type of disease. This article reviews the advancements in gene therapy for IEI, aiming to increase awareness and understanding of these disorders.
免疫出生错误（inborn errors of immunity, IEI）是由遗传因素导致免疫结构或功能障碍所致的一类疾病，可累及固有免疫和适应性免疫。2022年IEI新分类包含485种IEI，分为十大类疾病。近年来随着分子生物学的快速发展，许多IEI的具体发病机制得以揭示，使得基因治疗在该类疾病的临床前和临床研究成为可能。该文综述基因治疗在IEI中的研究和应用，以进一步提高临床医生对IEI诊治的认知。.

BACKGROUND: Severe combined immunodeficiency (SCID) is the most fatal form of inherited primary immunodeficiency disease. Known molecular defect mutations occur in most children with SCID.
METHODS: Herein, we report Adenosine Deaminase-SCID (ADA-SCID) using whole-exome sequencing (WES), explore exome mutational landscape and significance for 17 SCID samples, and verify the mutated exon genes using the Gene Expression Omnibus (GEO) datasets. A total of 250 patients, who were hospitalized at the Neonatal Intensive Care Unit (NICU) of The Seventh Medical Center of the PLA General Hospital for 3 years (from 2017 to 2020), were screened for SCID. We collected mutated genes from the WES data of 17 SCID children. GSE609 and GSE99176 cohorts were used to identify the expressions of mutated exon genes and molecular features in SCID. Gene set variation analyses (GSVA) and correlation analyses were performed.
RESULTS: The detection rate with approximately 6.8 % (17/250) of SCID is high in the NICU. A total of 16 genes were identified among 17 SCID samples, of which the Top 2 genes (MUC6 and RP11-683L23.1) might be crucial in the progression of SCID with 94 % mutation frequency. Furthermore, CNN2 and SCGB1C1 had significant co-mutations and may cooperate to affect SCID development. Importantly, the phylogenetic tree classification results of 17 SCID samples are more correlated to MUC6 with the most significant mutations. Expression profiles of seven mutated genes and five mutated genes were documented in GSE609 and GSE99176 cohorts based on microarray, respectively. Several immune-related pathways were significantly enriched, and Foxd4, differing from the other four mutated genes, was inversely correlated with the GSVA-enriched pathway.
CONCLUSIONS: Due to its high detection rate (6.8%) and fatality rate (100%), the inclusion of SCID in newborn screening (NBS) is urgent for children in China. The WES successfully identified several common exonic variants (e.g., MUC6) and depicted the feature of mutations and evolution, which will help develop new diagnostic methods for SCID.

AIOLOS, a vital member of the IKAROS protein family, plays a significant role in lymphocyte development and function through DNA binding and protein-protein interactions. Mutations in the IKZF3 gene, which encodes AIOLOS, lead to a rare combined immunodeficiency often linked with infections and malignancy. In this study, we evaluated a 1-year-4-month-old female patient presenting with recurrent infections, diarrhea, and failure to thrive. Laboratory investigations revealed decreased T lymphocyte and immunoglobulin levels. Through whole-exome and Sanger sequencing, we discovered a de novo mutation in IKZF3 (NM_012481; exon 5 c.571G > C, p.Gly191Arg), corresponding to the third DNA-binding zinc finger region of the encoded protein AIOLOS. Notably, the patient with the AIOLOS G191R mutation showed reduced recent thymic emigrants in naïve CD4+T cells compared to healthy counterparts of the same age, while maintaining normal levels of Th1, Th2, Th17, Treg, and Tfh cells. This mutation also resulted in decreased switched memory B cells and lower CD23 and IgM expression. In vitro studies revealed that AIOLOS G191R does not impact the expression of AIOLOS but compromises its stability, DNA binding and pericentromeric targeting. Furthermore, AIOLOS G191R demonstrated a dominant-negative effect over the wild-type protein. This case represents the first reported instance of a mutation in the third DNA-binding zinc finger region of AIOLOS highlighting its pivotal role in immune cell functionality.

Objective: To evaluate the efficacy of allogeneic hematopoietic stem cell transplantation for the treatment of combined immunodeficiency (CID) and explore prognostic risk factors. Methods: In this retrospective cohort study, clinical characteristics, laboratory tests and prognosis of 73 CID children who underwent allogeneic hematopoietic stem cell transplantation from February 2014 to April 2022 in the Children\'s Hospital of Fudan University were analyzed. Based on the subtypes of diseases, all patients were divided into severe combined immunodeficiency disease (SCID) group and other CID group. Based on the types of donors, all patients were divided into matched sibling donor group, matched unrelated donor group, unrelated cord blood group, and haploidentical donor group. Kaplan-Meier method and Log-Rank test were used to analyze the survival data. Cox regression was used to analyze prognostic factors. Results: Among the 73 patients, there were 61 (84%) males and 12 (16%) females. Fifty-five (75%) patients were SCID, and 18 (25%) patients were other CID. Donor source included 2 (3%) matched sibling donors (MSD), 3 (4%) matched unrelated donors (MUD), 64 (88%) unrelated cord blood (UCB), and 4 (5%) haploidentical donors. The age at transplant was 10.7 (5.9, 27.5) months, and the follow-up time was 36.2 (2.5, 62.9) months. The 3-year overall survival rate of 73 patients with CID was (67±6) %. No significant difference was found in the 3-year overall survival rates between patients with SCID (55 cases) and other CID (18 cases) ((64±7) % vs. (78±10) %, χ2=1.31, P=0.252). And no significant difference was found in the 3-year overall survival rates among patients who received MSD or MUD (5 cases), UCB (64 cases), and haploidentical donor (4 cases) transplant (100% vs. (66±6)% vs. (50±25) %, χ2=2.30, P=0.317). Cox regression analysis showed that the medical history of sepsis (HR=2.55, 95%CI 1.05-6.20, P=0.039) and hypoalbuminemia at transplant (HR=2.96, 95%CI 1.14-7.68, P=0.026) were independent risk factors for the prognosis of allogeneic hematopoietic stem cell transplantation in pediatric patients with CID. Conclusions: Allogeneic hematopoietic stem cell transplantation is an effective treatment for CID. The medical history of sepsis and hypoalbuminemia at transplant were risk factors for prognosis. Enhancing infection prevention and nutritional intervention before transplant can improve patient prognosis.
目的： 评价异基因造血干细胞移植治疗联合免疫缺陷病（CID）的效果并探讨预后相关因素。 方法： 回顾性队列研究。收集2014年2月至2022年4月复旦大学附属儿科医院行异基因造血干细胞移植治疗的73例CID患儿的临床特征、实验室检查及预后。根据疾病亚型分为重症联合免疫缺陷病（SCID）组和其他CID组，根据供者类型分为同胞相合供者组、非亲缘相合供者组、非亲缘脐带血组及单倍体供者组，采用Kaplan-Meier法对患儿进行生存分析并进行Log-Rank检验，Cox回归分析预后危险因素。 结果： 73例患儿中男61例（84%）、女12例（16%）。SCID 55例（75%），其他CID18例（25%）。同胞相合供者、非亲缘相合供者、非亲缘脐带血及单倍体供者分别为2例（3%）、3例（4%）、64例（88%）及4例（5%）。移植年龄10.7（5.9，27.5）月龄，随访时间36.2（2.5，62.9）个月。73例CID患儿的3年总生存率为（67±6）%。SCID组（55例）与其他CID组（18例）患儿3年总生存率差异无统计学意义［（64±7）%比（78±10）%，χ2=1.31，P=0.252］。同胞或非亲缘相合供者移植组（5例）、非亲缘脐带血移植组（64例）及单倍体供者移植组（4例）患儿3年总生存率分别为100%、（66±6）%、（50±25）%，组间比较差异无统计学意义（χ2=2.30，P=0.317）。Cox回归分析显示败血症病史（HR=2.55，95%CI 1.05~6.20，P=0.039）及移植前低白蛋白血症（HR=2.96，95%CI 1.14~7.68，P=0.026）是影响CID患儿移植预后的独立危险因素。 结论： 异基因造血干细胞移植治疗CID有效，移植前有败血症病史及低白蛋白血症是患儿预后危险因素，加强移植前感染预防及营养干预可改善患儿预后。.

Multiple intestinal atresia with combined immune deficiency is a severe autosomal recessive disorder caused by the tetratricopeptide repeat domain 7A (TTC7A) gene deficiency, which is characterized by extensive intestinal defects with immune deficiency. This report describes a fetus with TTC7A deficiency who developed meconium peritonitis in utero. Evidence suggests that patients with TTC7A deficiency present with intestinal defects as early as in utero. In this case, intestinal abnormalities were considered during the prenatal examination at week 28, and chromosome and genetic tests were performed. The results indicated that the fetus had a TTC7A complex heterozygous mutation. The male infant underwent surgical treatment after birth and developed severe infection and sepsis, which confirmed the presence of multiple intestinal atresia with combined immune deficiency. Our case suggests an association between meconium peritonitis and the TTC7A gene deficiency, indicating the possibility of severe intestinal defects and immune deficiencies after birth and guiding subsequent fetal treatment choices.

Severe combined immunodeficiency (SCID) is a group of fatal primary immunodeficiencies characterized by the severe impairment of T-cell differentiation. IL7R deficiency is a rare form of SCID that usually presents in the first months of life with severe and opportunistic infections, failure to thrive, and a high risk of mortality unless treated. Although recent improvements in early diagnosis have been achieved through newborn screening, few IL7R-related SCID patients had been reported in the Chinese population.
Here, we retrospectively analyzed a case of SCID in a 5-month-old girl with symptoms, including severe T-cell depletion, recurrent fever, oral ulcers, pneumonia, hepatosplenomegaly, bone marrow hemophagocytosis, and bacterial and viral infections. Whole-exome sequencing (WES), quantitative PCR (qPCR), and chromosome microarray analysis (CMA) were performed to identify the patient\'s genetic etiology. We identified a 268 kb deletion and a splicing variant, c.221 + 1G > A, in the proband. These two variants of IL7R were inherited from the father and mother.
To our knowledge, this is the first report of whole IL7R gene deletion in combination with a pathogenic splicing variant in a patient with SCID. This deletion also expands the pathogenic variation spectrum of SCID caused by IL7R. The incorporation of exome-based copy number variant analysis makes WES a powerful molecular diagnostic technique for the clinical diagnosis of pediatric patients.

Hemophagocytic lymphohistiocytosis triggered by disseminated Bacillus Calmette-Guerin infection is rare. Targeted next-generation sequencing for tuberculosis can rapidly identify different strains of Mycobacterium tuberculosis complex as well as drug resistance genes. Herein we report 2 cases of hemophagocytic lymphohistiocytosis in whom targeted next-generation sequencing rapidly identified Bacillus Calmette-Guerin as the infectious trigger.

UNASSIGNED: Hypomorphic mutations of DCLRE1C cause an atypical severe combined immunodeficiency (SCID), and Epstein-Barr virus (EBV)-related colon lymphoma is a rare complication.
UNASSIGNED: A teenage boy presented with colon EBV-related colon lymphoma, plantar warts, and a history of recurrent pneumonia. His peripheral blood lymphocyte count and serum level of immunoglobulin (Ig) G were normal, but he exhibited a T+B-NK+ immunophenotype. Genetic analysis by whole exome sequencing revealed compound heterozygous mutations of DCLRE1C (NM_001033855.3), including a novel paternal splicing donor mutation (c.109 + 2T>C) in intron 1, and a maternal c.1147C>T (p.R383X) nonsense mutation in exon 13. Based on his clinical features and genetic results, the diagnosis of atypical SCID with colon lymphoma was established. Our review shows that seven patients, including our patient, have been reported to develop lymphoma, all with hypomorphic DCLRE1C mutations. Among these cases, six had EBV-related B-cell lineage lymphoma, and one had Hodgkin lymphoma with EBV reactivation. Unfortunately, all of the patients died.
UNASSIGNED: Recognizing the radiosensitivity of the disease is critical for the prognosis. Hematopoietic stem cell transplantation before being infected with EBV is an optimal treatment.

重症联合免疫缺陷病（SCID）是致命的疾病，患儿常在生命早期出现反复、严重的感染，SCID的早期识别和诊断可以改善患儿生存率。病史是提示SCID诊断的重要线索，外周血T细胞数缺乏是SCID的主要诊断标准。一旦考虑SCID诊断，应立即制定治疗方案。.

Severe combined immunodeficiency (SCID) encompasses a range of inherited disorders that lead to a profound deterioration of the immune system. Among the pivotal genes associated with SCID, RAG1 and IL2RG play crucial roles. IL2RG is essential for the development, differentiation, and functioning of T, B, and NK cells, while RAG1 critically contributes to adaptive immunity by facilitating V(D)J recombination during the maturation of lymphocytes. Animal models carrying mutations in these genes exhibit notable deficiencies in their immune systems. Non-human primates (NHPs) are exceptionally well-suited models for biomedical research due to their genetic and physiological similarities to humans. Cytosine base editors (CBEs) serve as powerful tools for precisely and effectively modifying single-base mutations in the genome. Their successful implementation has been demonstrated in human cells, mice, and crop species. This study outlines the creation of an immunodeficient monkey model by deactivating both the IL2RG and RAG1 genes using the CBE4max system. The base-edited monkeys exhibited a severely compromised immune system characterized by lymphopenia, atrophy of lymphoid organs, and a deficiency of mature T cells. Furthermore, these base-edited monkeys were capable of hosting and supporting the growth of human breast cancer cells, leading to tumor formation. In summary, we have successfully developed an immunodeficient monkey model with the ability to foster tumor growth using the CBE4max system. These immunodeficiency monkeys show tremendous potential as valuable tools for advancing biomedical and translational research.