Successful bone marrow transplantation in a patient with Omenn syndrome, a rare variant of severe combined immunodeficiency syndrome: A case report.

Key Clinical Message: Bone marrow transplantation (BMT) saves lives in Omenn syndrome, a severe immunodeficiency disorder. Timely genetic diagnosis and matched donor BMT are crucial. Emphasis on newborn screening and multidisciplinary care improves outcomes for infants with inherited disorders. Prompt intervention and comprehensive management are vital for a successful transplant outcome. Abstract: Omenn syndrome represents a severe variant of combined immunodeficiency characterized by disregulated immune responses and susceptibility to recurrent infections. We present the case of a 3-month-old female infant initially presenting with upper respiratory infection symptoms and a diffuse rash, unresponsive to local treatment. At 4 months of age, the patient underwent allogeneic bone marrow transplantation (BMT) utilizing stem cells from a fully matched sibling donor. Pre-transplant conditioning included antimicrobial prophylaxis and supportive therapies. Following BMT, the patient received immunosuppressive medications to prevent graft rejection and graft-versus-host disease. Clinical monitoring post-transplant showed timely neutrophil and platelet engraftment, with subsequent follow-up demonstrating stable clinical parameters and negative cytomegalovirus status. The case highlights the importance of timely diagnosis and treatment in managing severe immunodeficiency disorders, demonstrating the potential for successful outcomes with appropriate timely interventions. Regular monitoring and follow-up appointments were crucial in ensuring the success of the treatment. This case also emphasizes the significance of multidisciplinary care and genetic testing in identifying and managing rare immunodeficiency disorders. The successful outcome in this case provides hope for improved treatment options and better patient outcomes in the future.

Omenn Syndrome in Two Infants with Different Hypomorphic Variants in Janus Kinase 3.

Biallelic null or hypomorphic variants in JAK3 cause SCID and less frequently Omenn syndrome. We investigated homozygous hypomorphic JAK3 mutations in two patients, and expression and function of a novel JAK3R431P variant in Omenn syndrome. Immunophenotyping of PBMC from the patient with the novel JAK3R431P variant was undertaken, by flow cytometry and Phosflow after stimulation with IL-2, IL-7, and IL-15. JAK3 expression was investigated by Western blotting. We report two patients with homozygous hypomorphic JAK3 variants and clinical features of Omenn syndrome. One patient had a previously described JAK3R775H variant, and the second had a novel JAK3R431P variant. One patient with a novel JAK3R431P variant had normal expression of JAK3 in immortalised EBV-LCL cells but reduced phosphorylation of STAT5 after stimulation with IL-2, IL-7, and IL-15 consistent with impaired kinase activity. These results suggest the JAK3R431P variant to be hypomorphic. Both patients are alive and well after allogeneic haematopoietic stem cell transplantation. They have full donor chimerism, restitution of thymopoiesis and development of appropriate antibody responses following vaccination. We expand the phenotype of hypomorphic JAK3 deficiency and demonstrate the importance of functional testing of novel variants in disease-causing genes.

Expanding the PRAAS spectrum: De novo mutations of immunoproteasome subunit ß-type 10 in six infants with SCID-Omenn syndrome.

Mutations in proteasome ß-subunits or their chaperone and regulatory proteins are associated with proteasome-associated autoinflammatory disorders (PRAAS). We studied six unrelated infants with three de novo heterozygous missense variants in PSMB10, encoding the proteasome ß2i-subunit. Individuals presented with T-B-NK± severe combined immunodeficiency (SCID) and clinical features suggestive of Omenn syndrome, including diarrhea, alopecia, and desquamating erythematous rash. Remaining T cells had limited T cell receptor repertoires, a skewed memory phenotype, and an elevated CD4/CD8 ratio. Bone marrow examination indicated severely impaired B cell maturation with limited V(D)J recombination. All infants received an allogeneic stem cell transplant and exhibited a variety of severe inflammatory complications thereafter, with 2 peri-transplant and 2 delayed deaths. The single long-term transplant survivor showed evidence for genetic rescue through revertant mosaicism overlapping the affected PSMB10 locus. The identified variants (c.166G>C [p.Asp56His] and c.601G>A/c.601G>C [p.Gly201Arg]) were predicted in silico to profoundly disrupt 20S immunoproteasome structure through impaired ß-ring/ß-ring interaction. Our identification of PSMB10 mutations as a cause of SCID-Omenn syndrome reinforces the connection between PRAAS-related diseases and SCID.

Heterogeneity in RAG1 and RAG2 deficiency: 35 cases from a single-centre.

Recombination activating genes (RAG)1 and RAG2 deficiency leads to combined T/B-cell deficiency with varying clinical presentations. This study aimed to define the clinical/laboratory spectrum of RAG1 and RAG2 deficiency. We retrospectively reviewed the clinical/laboratory data of 35 patients, grouped them as severe combined immunodeficiency (SCID), Omenn syndrome (OS), and delayed-onset combined immunodeficiency (CID) and reported nine novel mutations. The male/female ratio was 23/12. Median age of clinical manifestations was 1 months (mo) (0.5-2), 2 mo (1.25-5), and 14 mo (3.63-27), age at diagnosis was 4 mo (3-6), 4.5 mo (2.5-9.75), and 27 mo (14.5-70) in SCID (n = 25; 71.4%), OS (n = 5; 14.3%), and CID (n = 5; 14.3%) patients, respectively. Common clinical manifestations were recurrent sinopulmonary infections 82.9%, oral moniliasis 62.9%, diarrhea 51.4%, and eczema/dermatitis 42.9%. Autoimmune features were present in 31.4% of the patients; 80% were in CID patients. Lymphopenia was present in 92% of SCID, 80% of OS, and 80% of CID patients. All SCID and CID patients had low T (CD3, CD4, and CD8), low B, and increased NK cell numbers. Twenty-eight patients underwent hematopoietic stem cell transplantation (HSCT), whereas seven patients died before HSCT. Median age at HSCT was 7 mo (4-13.5). Survival differed in groups; maximum in SCID patients who had an HLA-matched family donor, minimum in OS. Totally 19 (54.3%) patients survived. Early molecular genetic studies will give both individualized therapy options, and a survival advantage because of timely diagnosis and treatment. Further improvement in therapeutic outcomes will be possible if clinicians gain time for HSCT.

Human Autosomal Recessive DNA Polymerase Delta 3 Deficiency Presenting as Omenn Syndrome.

The DNA polymerase δ complex (PolD), comprising catalytic subunit POLD1 and accessory subunits POLD2, POLD3, and POLD4, is essential for DNA synthesis and is central to genome integrity. We identified, by whole exome sequencing, a homozygous missense mutation (c.1118A > C; p.K373T) in POLD3 in a patient with Omenn syndrome. The patient exhibited severely decreased numbers of naïve T cells associated with a restricted T-cell receptor repertoire and a defect in the early stages of TCR recombination. The patient received hematopoietic stem cell transplantation at age 6 months. He manifested progressive neurological regression and ultimately died at age 4 years. We performed molecular and functional analysis of the mutant POLD3 and assessed cell cycle progression as well as replication-associated DNA damage. Patient fibroblasts showed a marked defect in S-phase entry and an enhanced number of double-stranded DNA break-associated foci despite normal expression levels of PolD components. The cell cycle defect was rescued by transduction with WT POLD3. This study validates autosomal recessive POLD3 deficiency as a novel cause of profound T-cell deficiency and Omenn syndrome.

Omenn syndrome in a 10-month-old male with athymia and VACTERL association.

We describe the case of a 10-month-old boy with vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities (VACTERL) association and athymia who developed Omenn syndrome.

Immunological assessment of a patient with Omenn syndrome resulting from compound heterozygous mutations in the RAG1 gene.

The recombination activating gene 1 (RAG1) is essential for V(D)J recombination during T- and B-cell development. In this study, we presented a case study of a 41-day-old female infant who exhibited symptoms of generalized erythroderma, lymphadenopathy, hepatosplenomegaly, and recurrent infections including suppurative meningitis and septicemia. The patient showed a T+B-NK+ immunophenotype. We observed an impaired thymic output, as indicated by reduced levels of naive T cells and sjTRECs, coupled with a restricted TCR repertoire. Additionally, T-cell CFSE proliferation was impaired, indicating a suboptimal T-cell response. Notably, our data further revealed that T cells were in an activated state. Genetic analysis revealed a previously reported compound heterozygous mutation (c. 1186C > T, p. R396C; c. 1210C > T, p. R404W) in the RAG1 gene. Structural analysis of RAG1 suggested that the R396C mutation might lead to the loss of hydrogen bonds with neighboring amino acids. These findings contribute to our understanding of RAG1 deficiency and may have implications for the development of novel therapies for patients with this condition.

Lymphocyte disturbance and functional assessment of the [Asp521Asn] ZAP70 mutation.

Activated zeta-chain-associated protein kinase 70 (ZAP70) phosphorylates the TCRαß:CD3:zeta complex to diversify and amplify TCR signaling. Patients with ZAP70 mutations can present with phenotypes of immune dysregulation as well as infection. We identified the first Taiwanese boy with the [Asp521Asn] ZAP70 mutation who presented with recurrent pneumonia, inflammatory bowel disease-like diarrhea, transient hematuria and autoimmune hepatitis. He had isolated CD8 lymphopenia, eosinophilia, hypogammaglobulinemia, and impaired lymphocyte proliferation. Downstream CD3/CD28 signaling, phosphorylation of AKT, ZAP70 and Ca2+ influx were decreased in [Asp521Asn] ZAP70 lymphocytes. Immunophenotyping analysis revealed expansion of transitional B and CD21-low B cells, Th2-skewing T follicular helper cells, but lower Treg cells. The Asp521Asn-ZAP70 hindered TCR-CD3 downstream phosphorylation and disturbed lymphocyte subgroup "profiles" leading to autoimmunity/autoinflammation. Further large-scale studies are warranted to clarify this lymphocyte disturbance. The prognosis significantly depends on hematopoietic stem cell transplantation, but not the genotype, the presence of opportunistic infections or immune dysregulation.

Concomitant Langerhans and Interdigitating Reticulum Cell Hyperplasia in a Reactive Lymph Node of an Infant with Omenn Syndrome: A Diagnostic Pitfall for Langerhans Cell Histiocytosis.

Omenn syndrome, a rare form of combined immunodeficiency in infants, presenting with recurrent infections, erythroderma, lymphadenopathy, hepatosplenomegaly, eosinophilia, and increased serum IgE levels. It is a fatal condition unless treated by hematopoietic stem cell transplant. Hence, an early diagnosis and a prompt treatment can lead to better outcome in these unfortunate babies afflicted with Omenn syndrome. Here, we present an 8-week-old infant with typical features of Omenn syndrome, both clinically as well as on laboratory analysis, but surprising immunohistochemical findings on lymph node biopsy.

The diagnosis of severe combined immunodeficiency: Implementation of the PIDTC 2022 Definitions.

BACKGROUND: Shearer et al in 2014 articulated well-defined criteria for the diagnosis and classification of severe combined immunodeficiency (SCID) as part of the Primary Immune Deficiency Treatment Consortium's (PIDTC's) prospective and retrospective studies of SCID. OBJECTIVE: Because of the advent of newborn screening for SCID and expanded availability of genetic sequencing, revision of the PIDTC 2014 Criteria was needed. METHODS: We developed and tested updated PIDTC 2022 SCID Definitions by analyzing 379 patients proposed for prospective enrollment into Protocol 6901, focusing on the ability to distinguish patients with various SCID subtypes. RESULTS: According to PIDTC 2022 Definitions, 18 of 353 patients eligible per 2014 Criteria were considered not to have SCID, whereas 11 of 26 patients ineligible per 2014 Criteria were determined to have SCID. Of note, very low numbers of autologous T cells (<0.05 × 109/L) characterized typical SCID under the 2022 Definitions. Pathogenic variant(s) in SCID-associated genes was identified in 93% of patients, with 7 genes (IL2RG, RAG1, ADA, IL7R, DCLRE1C, JAK3, and RAG2) accounting for 89% of typical SCID. Three genotypes (RAG1, ADA, and RMRP) accounted for 57% of cases of leaky/atypical SCID; there were 13 other rare genotypes. Patients with leaky/atypical SCID were more likely to be diagnosed at more than age 1 year than those with typical SCID lacking maternal T cells: 20% versus 1% (P < .001). Although repeat testing proved important, an initial CD3 T-cell count of less than 0.05 × 109/L differentiated cases of typical SCID lacking maternal cells from leaky/atypical SCID: 97% versus 7% (P < .001). CONCLUSIONS: The PIDTC 2022 Definitions describe SCID and its subtypes more precisely than before, facilitating analyses of SCID characteristics and outcomes.

The diagnosis of severe combined immunodeficiency (SCID): The Primary Immune Deficiency Treatment Consortium (PIDTC) 2022 Definitions.

Severe combined immunodeficiency (SCID) results from defects in the differentiation of hematopoietic stem cells into mature T lymphocytes, with additional lymphoid lineages affected in particular genotypes. In 2014, the Primary Immune Deficiency Treatment Consortium published criteria for diagnosing SCID, which are now revised to incorporate contemporary approaches. Patients with typical SCID must have less than 0.05 × 109 autologous T cells/L on repetitive testing, with either pathogenic variant(s) in a SCID-associated gene, very low/undetectable T-cell receptor excision circles or less than 20% of CD4 T cells expressing naive markers, and/or transplacental maternally engrafted T cells. Patients with less profoundly impaired autologous T-cell differentiation are designated as having leaky/atypical SCID, with 2 or more of these: low T-cell numbers, oligoclonal T cells, low T-cell receptor excision circles, and less than 20% of CD4 T cells expressing naive markers. These patients must also have either pathogenic variant(s) in a SCID-associated gene or reduced T-cell proliferation to certain mitogens. Omenn syndrome requires a generalized erythematous rash, absent transplacentally acquired maternal engraftment, and 2 or more of these: eosinophilia, elevated IgE, lymphadenopathy, hepatosplenomegaly. Thymic stromal defects and other causes of secondary T-cell deficiency are excluded from the definition of SCID. Application of these revised Primary Immune Deficiency Treatment Consortium 2022 Definitions permits precise categorization of patients with T-cell defects but does not imply a preferred treatment strategy.

Whole-exome sequencing identified a homozygous novel RAG1 mutation in a child with omenn syndrome.

INTRODUCTION AND OBJECTIVES: Omenn syndrome (OS) is a very rare type of severe combined immunodeficiencies manifested with erythroderma, eosinophilia, hepatosplenomegaly, lymph-adenopathy, and elevated level of serum IgE. OS is inherited with an autosomal recessive mode of inheritance. Germline mutations in the human RAG1 gene cause OS. MATERIALS AND METHODS: In this study, we investigated a 2-month-old boy with cough, mild anaemia, pneumonia, immunodeficiency, repeated infection, feeding difficulties, hepatomegaly, growth retardation, and heart failure. Parents of the proband were phenotypically normal. RESULTS: Karyotype analysis and chromosomal microarray analysis found no chromosomal structural abnormalities (46, XY) and no pathogenic copy number variations (CNVs) in the proband. Whole-exome sequencing identified a novel homozygous single nucleotide deletion (c.2662delC) in exon 2 of the RAG1 gene in the proband. Sanger sequencing confirmed that both the proband parents were carrying this variant in a heterozygous state. This variant was not identified in two elder sisters and one elder brother of the proband and in the 100 ethnically matched normal healthy individuals. This novel homozygous deletion (c.2662delC) leads to the frameshift, which finally results in the formation of the truncated protein (p.Leu888Phefs*3) V(D)J recombination-activating protein 1 with 890 amino acids compared with the wildtype V(D)J recombination-activating protein 1 of 1043 amino acids. Hence, it is a loss-of-function variant. CONCLUSIONS: Our present study expands the mutational spectrum of the RAG1 gene associated with OS. We also strongly suggested the importance of whole-exome sequencing for the genetic screening of patients with OS.

Inborn Errors of Immunity With Fetal or Perinatal Clinical Manifestations.

In this article we revised the literature on Inborn Errors of Immunity (IEI) keeping our focus on those diseases presenting with intrauterine or perinatal clinical manifestations. We opted to describe our findings according to the IEI categories established by the International Union of Immunological Societies, predominantly addressing the immunological features of each condition or group of diseases. The main finding is that such precocious manifestations are largely concentrated in the group of primary immune regulatory disorders (PIRDs) and not in the group of classical immunodeficiencies. The IEI categories with higher number of immunological manifestations in utero or in perinatal period are: (i) diseases of immune dysregulation (HLH, IPEX and other Tregopathies, autosomal recessive ALPS with complete lack of FAS protein expression) and (ii) autoinflammatory diseases (NOMID/CINCA, DIRA and some interferonopathies, such as Aicardi-Goutières syndrome, AGS, and USP18 deficiency). Regarding the other IEI categories, some patients with Omenn syndrome (an atypical form of SCID), and a few X-linked CGD patients present with clinical manifestations at birth associated to immune dysregulation. The most frequent clinical features were hydrops fetalis, intrauterine growth retardation leading to fetal loss, stillbirths, and prematurity, as in HLH and IPEX. Additionally, pseudo-TORCH syndrome was observed in AGS and in USP18 deficiency. The main goal of our review was to contribute to increasing the medical awareness of IEI with intrauterine and perinatal onset, which has obvious implications for diagnosis, treatment, and genetic counseling.

An infant with omenn syndrome: A case report.

BACKGROUND: Omenn syndrome is a rare, autosomal recessive disorder. It is a disorder that stems from severe combined immunodeficiency in an affected individual. The disease is also of rare occurrence in children in Pakistan because this is the age where this disease usually presents, after having developed in the child. This case report will explore all the reasons that lead to the occurrence of this syndrome while also reflecting on the management profile of the child. CASE PRESENTATION: This case report deals with the discussion of one such child who was diagnosed with Omenn Syndrome after being diagnosed with several other diseases, which were being mistaken for being the actual problem and disease, but the reality was that the child was suffering from Omenn syndrome. DISCUSSION: The child is only 3 months old and his symptoms pose a great risk to his overall health status while also making him predisposed to develop several complications and nutritional deficiencies as a result, all of which keep on adding to the burden of diseases that the child faced. In Omenn syndrome, there is an increased susceptibility to develop infections of the skin, lungs, joints, as well as sepsis. Usually, the death of the patient ensues due to pneumonia and septicemia or septic shock. CONCLUSION: Omenn syndrome is a rare disease caused by missense mutations in the recombinase activating genes. It can be treated by bone marrow transplantation or lymphocytic stimulation depending on the severity of the presenting underlying immunodeficiency.

Successful hematopoietic stem cell transplantation with reduced dose of busulfan for Omenn syndrome.

Omenn syndrome (OS) is typically observed in the autosomal recessive form of severe combined immunodeficiency (SCID) with autoreactive manifestations, and it requires allogeneic hematopoietic stem cell transplantation. Unlike non-OS SCID, a conditioning regimen is usually required to eradicate T-cells; however, optimal conditioning regimens are not established mainly because of the rarity of OS. Here, we report a case of hematopoietic stem cell transplantation with a reduced dose of busulfan, as a conditioning regimen and successful engraftment with complete chimerism. OS was diagnosed in a one-month-old boy based on a diffuse erythematous rash, absent B-cells, and activated T-cells. Genetic analysis failed to identify causative mutations for OS/SCID, such as RAG1/2. Bone marrow transplantation was performed from his HLA-matched sister with a conditioning regimen consisting of targeted busulfan, fludarabine, and anti-thymocyte globulin. Cyclosporine had been administered before transplantation to control abnormal T-cell activation and continued for graft-versus-host disease (GVHD) prophylaxis. Engraftment was achieved on day 12, and no GVHD symptoms were observed. For stem cell transplantation for OS, prior control of autoreactive symptoms with immunosuppressants is important for safe transplantation and reduced intensity conditioning (RIC) can be an option to achieve sustained engraftment.

Giant Cell Myocarditis in Children: Elusive Giant Cells Might Not Be the Only Clue.

Giant cell myocarditis (GCM) is a form of fulminant myocarditis that is rapidly progressive and frequently lethal even in children. Over the course of 20 years, a definitive histopathologic diagnosis of GCM has been made at our institution in only two pediatric patients, and in neither instance was the diagnosis of GCM rendered on initial cardiac biopsy. We present the two patients and highlight the similarities in their clinical presentation and their challenging and inconclusive- albeit histologically similar- initial cardiac biopsy findings.

Prenatal ultrasound diagnostic approach to Omenn syndrome: case report / Aproximación diagnóstica ultrasonográfica prenatal al síndrome de Omenn: reporte de caso

Objective: To report the case of a pregnant woman with ultrasound diagnosis of altered fetal tegumental system and postnatal diagnosis of Omenn syndrome. Case presentation: A 27-year-old patient who presented at 31 weeks of gestation with prenatal ultrasound evidence of a fetus with significant scalp edema, echogenic amniotic fluid and scaly abdominal skin, with ichtyosis variant impression on diagnostic ultrasound. The baby was born with congenital erythroderma complicated with skin infection, and later developed septic shock and died. The genetic and pathologic workup led to the conclusion of Omenn syndrome. Conclusion: Omenn syndrome must be considered as part of the differential diagnoses when prenatal ultrasound shows findings of altered tegument system. Studies are required to assess the accuracy of ultrasound for prenatal diagnosis of erythroderma.

Objetivo: reportar el caso de una gestante con diagnóstico ultrasonográfico de alteración del sistema tegumentario fetal y diagnóstico posnatal de síndrome de Omenn. Presentación de caso: se presenta el caso de paciente de 27 años con embarazo de 31 semanas, con exploración ultrasonográfica prenatal que evidencia feto con edema significativo del cuero cabelludo, líquido amniótico ecogénico y descamación de la piel abdominal, con aproximación diagnóstica ultrasonográfica de variante de ictiosis. El recién nacido presentó eritrodermia congénita complicada con infección de piel, con posterior choque séptico y muerte. El estudio genético y patológico concluye síndrome de Omenn. Conclusión: el síndrome de Omenn debe ser tomado en cuenta en los diagnósticos diferenciales cuando en la ultrasonografía prenatal existan hallazgos ultrasongráficos de una alteración del sistema tegumentario. Se requieren estudios que evalúen la exactitud del ultrasonido en el diagnóstico antenatal de las eritrodermias.

Aproximación diagnóstica ultrasonográfica prenatal al síndrome de Omenn: reporte de caso / Prenatal ultrasound diagnostic approach to Omenn syndrome: case report

Objetivo: reportar el caso de una gestante con diagnóstico ultrasonográfico de alteración del sistema tegumentario fetal y diagnóstico posnatal de síndrome de Omenn. Presentación de caso: se presenta el caso de paciente de 27 años con embarazo de 31 semanas, con exploración ultrasonográfica prenatal que evidencia feto con edema significativo del cuero cabelludo, líquido amniótico ecogénico y descamación de la piel abdominal, con aproximación diagnóstica ultrasonográfica de variante de ictiosis. El recién nacido presentó eritrodermia congénita complicada con infección de piel, con posterior choque séptico y muerte. El estudio genético y patológico concluye síndrome de Omenn. Conclusión: el síndrome de Omenn debe ser tomado en cuenta en los diagnósticos diferenciales cuando en la ultrasonografía prenatal existan hallazgos ultrasongráficos de una alteración del sistema tegumentario. Se requieren estudios que evalúen la exactitud del ultrasonido en el diagnóstico antenatal de las eritrodermias.

Objective: To report the case of a pregnant woman with ultrasound diagnosis of altered fetal tegumental system and postnatal diagnosis of Omenn syndrome. Case presentation: A 27-year-old patient who presented at 31 weeks of gestation with prenatal ultrasound evidence of a fetus with significant scalp edema, echogenic amniotic fluid and scaly abdominal skin, with ichtyosis variant impression on diagnostic ultrasound. The baby was born with congenital erythroderma complicated with skin infection, and later developed septic shock and died. The genetic and pathologic workup led to the conclusion of Omenn syndrome. Conclusion: Omenn syndrome must be considered as part of the differential diagnoses when prenatal ultrasound shows findings of altered tegument system. Studies are required to assess the accuracy of ultrasound for prenatal diagnosis of erythroderma.

Clinical Manifestations, Mutational Analysis, and Immunological Phenotype in Patients with RAG1/2 Mutations: First Cases Series from Mexico and Description of Two Novel Mutations.

Mutations in recombinase activating genes 1 and 2 (RAG1/2) result in human severe combined immunodeficiency (SCID). The products of these genes are essential for V(D)J rearrangement of the antigen receptors during lymphocyte development. Mutations resulting in null-recombination activity in RAG1 or RAG2 are associated with the most severe clinical and immunological phenotypes, whereas patients with hypomorphic mutations may develop leaky SCID, including Omenn syndrome (OS). A group of previously unrecognized clinical phenotypes associated with granulomata and/or autoimmunity have been described as a consequence of hypomorphic mutations. Here, we present six patients from unrelated families with missense variants in RAG1 or RAG2. Phenotypes observed in these patients ranged from OS to severe mycobacterial infections and granulomatous disease. Moreover, we report the first evidence of two variants that had not been associated with immunodeficiency. This study represents the first case series of RAG1- or RAG2-deficient patients from Mexico and Latin America.