Human Inborn Errors Of Immunity Research Articles

Dynamic chromatin architecture identifies new autoimmune-associated enhancers for IL2 and novel genes regulating CD4+ T cell activation.

Genome-wide association studies (GWAS) have identified hundreds of genetic signals associated with autoimmune disease. The majority of these signals are located in non-coding regions and likely impact cis-regulatory elements (cRE). Because cRE function is dynamic across cell types and states, profiling the epigenetic status of cRE across physiological processes is necessary to characterize the molecular mechanisms by which autoimmune variants contribute to disease risk. We localized risk variants from 15 autoimmune GWAS to cRE active during TCR-CD28 co-stimulation of naïve human CD4+ T cells. To characterize how dynamic changes in gene expression correlate with cRE activity, we measured transcript levels, chromatin accessibility, and promoter-cRE contacts across three phases of naive CD4+ T cell activation using RNA-seq, ATAC-seq, and HiC. We identified ~1200 protein-coding genes physically connected to accessible disease-associated variants at 423 GWAS signals, at least one-third of which are dynamically regulated by activation. From these maps, we functionally validated a novel stretch of evolutionarily conserved intergenic enhancers whose activity is required for activation-induced IL2 gene expression in human and mouse, and is influenced by autoimmune-associated genetic variation. The set of genes implicated by this approach are enriched for genes controlling CD4+ T cell function and genes involved in human inborn errors of immunity, and we pharmacologically validated eight implicated genes as novel regulators of T cell activation. These studies directly show how autoimmune variants and the genes they regulate influence processes involved in CD4+ T cell proliferation and activation.

Human Inborn Errors of Immunity in Pyoderma Gangrenosum: A Systematic Review.

Pyoderma gangrenosum (PG) is a rare ulcerative neutrophilic dermatosis that can be associated with primary immunodeficiency. The pathogenesis of PG has not yet been elucidated, although contributions from dysregulation of the immune system in patients with apparent genetic predispositions have been postulated. We conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic review with the objective of identifying inborn errors of immunity in the presence of PG as well as their clinical characteristics of severity including number of PG lesions and anatomic areas affected, and treatment outcomes. A literature search was performed using PubMed/MEDLINE, Embase, Cochrane Library, and Web of Science through August 24, 2023, for studies published in English using the search terms: "pyoderma gangrenosum," "inborn error of immunity," "immune defect*," and a list of genetic mutations potentially associated with PG. Seventy-four cases of PG associated with inborn errors of immunity were identified. The results demonstrate an association of PG with a variety of inborn errors of immunity, including genetic mutations not classically associated with the condition. Genetic mutations such as BTK, IL1RN, ITGB2, LPIN2, MEFV, NFkB1, NLRP3, NLRP12, NOD2, PSMB8, PLCG2, PSTPIP1, RAG1, TTC37, and WDR1, as well as complement component 2/complement component 4 (C2/C4) and complement component 7 (C7) deficiencies were identified in the presence of either idiopathic or syndromic PG. Of note, mutations in genes such as PSMB8, NLRP3, and IL1RN were found to be associated with a more severe and atypical course of PG, whereas mutations in RAG1 as well as those causing a C2/C4 deficiency were associated with the mildest clinical presentations of PG. Mutations in NFkB1, ITGB2, and PSTPIP1 were associated with the most heterogeneous clinical presentations. Human inborn errors of immunity may be implicated in the genetic predisposition to PG and may influence the clinical presentation. Due to the rarity of these diseases, further work must be done to describe the association between inborn errors of immunity and PG. Identifying inborn errors of immunity that may contribute to the development of PG may assist in further elucidating the mechanism of PG, guiding targeted treatment, and improving clinical outcomes for these patients.

Electronic health record signatures identify undiagnosed patients with common variable immunodeficiency disease.

Human inborn errors of immunity include rare disorders entailing functional and quantitative antibody deficiencies due to impaired B cells called the common variable immunodeficiency (CVID) phenotype. Patients with CVID face delayed diagnoses and treatments for 5 to 15 years after symptom onset because the disorders are rare (prevalence of ~1/25,000), and there is extensive heterogeneity in CVID phenotypes, ranging from infections to autoimmunity to inflammatory conditions, overlapping with other more common disorders. The prolonged diagnostic odyssey drives excessive system-wide costs before diagnosis. Because there is no single causal mechanism, there are no genetic tests to definitively diagnose CVID. Here, we present PheNet, a machine learning algorithm that identifies patients with CVID from their electronic health records (EHRs). PheNet learns phenotypic patterns from verified CVID cases and uses this knowledge to rank patients by likelihood of having CVID. PheNet could have diagnosed more than half of our patients with CVID 1 or more years earlier than they had been diagnosed. When applied to a large EHR dataset, followed by blinded chart review of the top 100 patients ranked by PheNet, we found that 74% were highly probable to have CVID. We externally validated PheNet using >6 million records from disparate medical systems in California and Tennessee. As artificial intelligence and machine learning make their way into health care, we show that algorithms such as PheNet can offer clinical benefits by expediting the diagnosis of rare diseases.

Primary immune regulatory disorders (PIRD): expanding the mutation spectrum in Turkey and identification of sixteen novel variants

Human Inborn Errors of Immunity (IEIs) encompass a clinically and genetically heterogeneous group of disorders, ranging from mild cases to severe, life-threatening types. Among these, Primary Immune Regulatory Disorders (PIRDs) constitute a subset of IEIs characterized by diverse clinical phenotypes, prominently featuring severe atopy, autoimmunity, lymphoproliferation, hyperinflammation, autoinflammation, and susceptibility to malignancies. According to the latest report from the International Union of Immunological Societies (IUIS), PIRDs arise from mutations in various genes including LYST, RAB27A, AP3B1, AP3D1, PRF1, UNC13D, STX11, STXBP2, FAAP24, SLC7A7, RASGRP1, CD70, CTPS1, RLTPR, ITK, MAGT1, PRKCD, TNFRSF9, SH2DIA, XIAP, CD27 (TNFRSF7), FAS (TNFRSF6), FASLG (TNFSF6), CASP10, CASP8, FADD, LRBA, STAT3, AIRE, ITCH, ZAP70, TPP2, JAK1, PEPD, FOXP3, IL2RA, CTLA4, BACH2, IL2RB, DEF6, FERMT1, IL10, IL10RA, IL10RB, NFAT5, TGFB1, and RIPK1 genes. We designed a targeted next-generation sequencing (TNGS) workflow using the Ion AmpliSeq™ Primary Immune Deficiency Research Panel to sequence 264 genes associated with IEIs on the Ion S5™ Sequencer. In this study, we report the identification of 38 disease-causing variants, including 16 novel ones, detected in 40 patients across 15 distinct PIRD genes. The application of next-generation sequencing enabled rapid and precise diagnosis of patients with PIRDs.

Autoimmune cytopenia and Kabuki syndrome in paediatrics: Insights in 11 patients.

Kabuki syndrome (KS) is now listed in the Human Inborn Errors of Immunity (IEI) Classification. It is a rare disease caused by KMT2D and KDM6A variants, dominated by intellectual disability and characteristic facial features. Recurrently, pathogenic variants are identified in those genes in patients examined for autoimmune cytopenia (AIC), but interpretation remains challenging. This study aims to describe the genetic diagnosis and the clinical management of patients with paediatric-onset AIC and KS. Among 11 patients with AIC and KS, all had chronic immune thrombocytopenic purpura, and seven had Evans syndrome. All had other associated immunopathological manifestations, mainly symptomatic hypogammaglobinaemia. They had a median of 8 (5-10) KS-associated manifestations. Pathogenic variants were detected in KMT2D gene without clustering, during the immunological work-up of AIC in three cases, and the clinical strategy to validate them is emphasized. Eight patients received second-line treatments, mainly rituximab and mycophenolate mofetil. With a median follow-up of 17 (2-31) years, 8/10 alive patients still needed treatment for AIC. First-line paediatricians should be able to recognize and confirm KS in children with ITP or multiple AIC, to provide early appropriate clinical management and specific long-term follow-up. The epigenetic immune dysregulation in KS opens exciting new perspectives.

Safety and efficacy of biologic immunosuppressive treatment in juvenile idiopathic arthritis associated with inborn errors of immunity.

This study aims to describe clinical features, therapeutic outcomes, and safety profiles in patients affected by juvenile idiopathic arthritis (JIA) and inborn errors of immunity (IEI) treated with biological Disease-modifying antirheumatic drugs (DMARDs). We enrolled three patients who were followed in the Pediatric Rheumatology Unit at Meyer Children's Hospital in Florence; these patients were affected by JIA, according to ILAR criteria, and IEI, according to the IUIS Phenotypical Classification for Human Inborn Errors of Immunity. Among them, two patients had 22q11.2 deletion syndrome (22q11.2DS) and one patient had X-linked agammaglobulinemia (XLA). Case 1: A 6-year and 2-month-old boy was affected by 22q11.2DS, associated with oligoarticular JIA, at the age of 2 years. He was treated with non-steroidal anti-inflammatory drugs (NSAIDs) and methotrexate, along with oral glucocorticoids but with no benefits. Treatment with etanercept allowed him to achieve remission after 10 months. Case 2: A 6-year and 2-month-old girl was affected by 22q11.2DS, associated with oligoarticular JIA, at the age of 3 years and 11 months. She was treated with NSAIDs, joint injections, and methotrexate but without clinical response. Treatment with Adalimumab allowed her to achieve remission after 6 months. Case 3: A 12-year and 2-month-old boy was affected by XLA, associated with polyarticular JIA, at the age of 9 years and 11 months. He was treated with NSAIDs, methotrexate, joint injections, and oral glucocorticoids with no benefits. He failed to respond to anti-TNF-alpha, tocilizumab, and abatacept. Currently, he is undergoing therapy with sirolimus plus abatacept, which allowed him to achieve remission after 4 months. Results suggest that the use of immunosuppressive biological therapies can control disease activity in these patients. No adverse drug-related reactions were observed during the follow-up.

Enrichment of Immune Dysregulation Disorders in Adult Patients with Human Inborn Errors of Immunity

Human inborn errors of immunity (IEI) comprise a group of diseases resulting from molecular variants that compromise innate and adaptive immunity. Clinical features of IEI patients are dominated by susceptibility to a spectrum of infectious diseases, as well as autoimmune, autoinflammatory, allergic, and malignant phenotypes that usually appear in childhood, which is when the diagnosis is typically made. However, some IEI patients are identified in adulthood due to symptomatic delay of the disease or other reasons that prevent the request for a molecular study. The application of next-generation sequencing (NGS) as a diagnostic technique has given rise to an ever-increasing identification of IEI-monogenic causes, thus improving the diagnostic yield and facilitating the possibility of personalized treatment. This work was a retrospective study of 173 adults with IEI suspicion that were sequenced between 2005 and 2023. Sanger, targeted gene-panel, and whole exome sequencing were used for molecular diagnosis. Disease-causing variants were identified in 44 of 173 (25.43%) patients. The clinical phenotype of these 44 patients was mostly related to infection susceptibility (63.64%). An enrichment of immune dysregulation diseases was found when cohorts with molecular diagnosis were compared to those without. Immune dysregulation disorders, group 4 from the International Union of Immunological Societies Expert Committee (IUIS), were the most prevalent among these adult patients. Immune dysregulation as a new item in the Jeffrey Model Foundation warning signs for adults significantly increases the sensitivity for the identification of patients with an IEI-producing molecular defect.

Inborn errors of immunity with kidney and urinary tract disorders: a review.

Human inborn errors of immunity (IEIs), previously referred to as primary immunodeficiency disorders (PIDs), are a heterogeneous spectrum of inherited abnormalities of the immune system with different organ involvement. The number of identified IEIs is rapidly increasing, highlighting the non-negligible role of an interdisciplinary approach in clinical diagnosis. Kidney disorders are one of the important comorbidities in some of the affected patients and play a significant role in the diagnosis and course of disease. According to recent studies, 22 types of human IEI with renal manifestations have been identified so far, including immunodeficiency with congenital thrombocytopenia, thymic defects with additional congenital anomalies, complement deficiencies, type 1 interferonopathies, immunity related to non-hematopoietic tissues, congenital neutropenia's, common variable immunodeficiency disorder (CVID) phenotype and immuno-osseous dysplasia. Based on this classification, we herein review IEIs with renal features and explain the genetic defect, inheritance, and type of renal manifestations.

Human inborn errors of immunity associated with IRF4.

The transcription factor interferon regulatory factor 4 (IRF4) belongs to the IRF family and has several important functions for the adaptive immune response. Mutations affecting IRF family members IRF1, IRF3, IRF7, IRF8, or IRF9 have been described in patients presenting with inborn errors of immunity (IEI) highlighting the importance of these factors for the cellular host defense against mycobacterial and/or viral infections. IRF4 deficiency and haploinsufficiency have been associated with IEI. More recently, two novel IRF4 disease-causing mechanisms have been described due to the characterization of IEI patients presenting with cellular immunodeficiency associated with agammaglobulinemia. Here, we review the phenotypes and physiopathological mechanisms underlying IEI of IRF family members and, in particular, IRF4.

Newborn screening for severe combined immunodeficiency: changing the landscape of post-transplantation survival

Severe combined immunodeficiency (SCID) represents a group of rare monogenic immune disorders resulting from defects of the adaptive immune system. Affected patients have a high risk of fatal outcome in infancy mainly due to early overwhelming infections. 1 Tangye SG Al-Herz W Bousfiha A et al. Human inborn errors of immunity: 2022 update on the classification from the International Union of Immunological Societies Expert Committee. J Clin Immunol. 2022; 42: 1473-1507 Crossref PubMed Scopus (134) Google Scholar Hence, timely diagnosis and therapeutic interventions shortly after birth are vital. The gold standard of treatment for SCID is allogeneic haematopoietic stem cell transplantation (HSCT), which can provide a functional immune system and is lifesaving. Measuring the effect of newborn screening on survival after haematopoietic cell transplantation for severe combined immunodeficiency: a 36-year longitudinal study from the Primary Immune Deficiency Treatment ConsortiumPopulation-based newborn screening has facilitated the identification of infants with SCID early in life, in turn leading to prompt HCT while avoiding infections. Public health programmes worldwide can benefit from this definitive demonstration of the value of newborn screening for SCID. Full-Text PDF

Malignancy-associated immune responses: Lessons from human inborn errors of immunity.

It is widely understood that cancer is a significant cause of morbidity and mortality worldwide. Despite numerous available treatments, prognosis for many remains poor, thus, the development of novel therapies remains essential. Given the incredible success of many immunotherapies in this field, the important contribution of the immune system to the control, and elimination, of malignancy is clear. While many immunotherapies target higher-order pathways, for example, through promoting T-cell activation via immune checkpoint blockade, the potential to target specific immunological pathways is largely not well researched. Precisely understanding how immunity can be tailored to respond to specific challenges is an exciting idea with great potential, and may trigger the development of new therapies for cancer. Inborn Errors of Immunity (IEI) are a group of rare congenital disorders caused by gene mutations that result in immune dysregulation. This heterogeneous group, spanning widespread, multisystem immunopathology to specific immune cell defects, primarily manifest in immunodeficiency symptoms. Thus, these patients are particularly susceptible to life-threatening infection, autoimmunity and malignancy, making IEI an especially complex group of diseases. While precise mechanisms of IEI-induced malignancy have not yet been fully elucidated, analysis of these conditions can highlight the importance of particular genes, and downstream immune responses, in carcinogenesis and may help inform mechanisms which can be utilised in novel immunotherapies. In this review, we examine the links between IEIs and cancer, establishing potential connections between immune dysfunction and malignancy and suggesting roles for specific immunological mechanisms involved in preventing carcinogenesis, thus, guiding essential future research focused on cancer immunotherapy and providing valuable insight into the workings of the immune system in both health and disease.

From second thoughts on the germ theory to a full-blown host theory

In 1955, René Dubos famously expressed his “second thoughts on the germ theory”, attributing infectious diseases to various “changing circumstances” that weaken the host by unknown mechanisms. He rightly stressed that only a small minority of individuals infected by almost any microbe develop clinical disease. Intriguingly, though, he did not mention the abundant and elegant findings reported from 1905 onward that unambiguously pointed to host genetic determinants of infection outcome in plants and animals, including human inborn errors of immunity. Diverse findings over the next 50 y corroborated and extended these earlier genetic and immunological observations that René Dubos had neglected. Meanwhile, the sequential advent of immunosuppression- and HIV–driven immunodeficiencies unexpectedly provided a mechanistic basis for his own views. Collectively, these two lines of evidence support a host theory of infectious diseases, with inherited and acquired immunodeficiencies as the key determinants of severe infection outcome, relegating the germ to an environmental trigger that reveals an underlying and preexisting cause of disease and death.

Father and son are carriers of two different types of human inborn errors of immunity: a case report

IntroductionChronic granulomatous disease (CGD) is an inborn error of immunity (IEI) characterized by recurrent bacterial and fungal infections of skin, airways, liver, brain and bones with the estimated prevalence of 1 in 250,000 live births. CGD can inherited either in an X-linked (allelic variants in the CYBB gene) or autosomal recessive mode (allelic variants in the CYBA, NCF1, NCF2, NCF4, and CYBC1 genes). Wiskott-Aldrich syndrome is an X-linked disorder with an estimated incidence of 1 in 100 000 live male births caused by variants in the WAS gene, characterized by microthrombocytopenia, eczema, recurrent infections, increased risk for autoimmune disease and malignancy. Materials and MethodsIn this case report, we present our experience about two cases of blood relatives diagnosed with different types of human inborn errors of immunity. Genetic analysis of CYBB gene in 2007 was performed by Sanger sequencing and of WAS gene in 2022 by next generation amplicon sequencing. All subjects consented to the study. ResultsThe first case was a 15-year-old male (1992 y.o.b., proband) who was diagnosed as X-linked CGD patient in 2007 due to his clinical history and hemizygote allelic variant in the CYBB gene (NM_000397.4: c.484–1G>T, COSV101059810). The second case was a 2-month-old boy (biological son of proband) who was hospitalized in 2022 due to microthrombocytopenia, low platelet volume, cytomegalovirus infection, mild anemia. Genetic analysis revealed in the DNA sample of the second case the hemizygote allelic variant in the WAS gene (NM_000377.3: c.777 +3_777+6del GAGT). Genetic testing didn’t reveal such variant in the DNA sample of the proband's wife, that's why this variant was classified as “de novo”. ConclusionInborn errors of immunity (IEI) present clinically as increased susceptibility to infections, autoimmunity, autoinflammatory diseases, allergy, bone marrow failure, and/or malignancy. There are now a total of 485 IEI, which are segregating to 10 groups of disorders into overlapping phenotypes. Despite the fact that IEI are rare diseases, we have shown that even in one family two different types of disorders can occur. In our case the second IEI was occur due to spontaneously alterations during the process of DNA replication during cell division.

Inborn Error of STAT2-Dependent IFN-I Immunity in a Patient Presented with Hemophagocytic Lymphohistiocytosis and Multisystem Inflammatory Syndrome in Children.

Human inborn errors of immunity (IEI) affecting the type I interferon (IFN-I) induction pathway have been associated with predisposition to severe viral infections. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening systemic hyperinflammatory syndrome that has been increasingly associated with inborn errors of IFN-I-mediated innate immunity. Here is reported a novel case of complete deficiency of STAT2 in a 3-year-old child that presented with typical features of HLH after mumps, measles, and rubella vaccination at the age of 12months. Due to the life-threatening risk of viral infection, she received SARS-CoV-2 mRNA vaccination. Unfortunately, she developed multisystem inflammatory syndrome in children (MIS-C) after SARS-CoV-2 infection, 4months after the last dose. Functional studies showed an impaired IFN-I-induced response and a defective IFNα expression at later stages of STAT2 pathway induction. These results suggest a possible more complex mechanism for hyperinflammatory reactions in this type of patients involving a possible defect in the IFN-I production. Understanding the cellular and molecular links between IFN-I-induced signaling and hyperinflammatory syndromes can be critical for the diagnosis and tailored management of these patients with predisposition to severe viral infection.

Infections in Inborn Errors of Immunity with Combined Immune Deficiency: A Review.

Enhanced susceptibility to microbes, often resulting in severe, intractable and frequent infections due to usually innocuous organisms at uncommon sites, is the most striking feature in individuals with an inborn error of immunity. In this narrative review, based on the International Union of Immunological Societies' 2022 (IUIS 2022) Update on phenotypic classification of human inborn errors of immunity, the focus is on commonly encountered Combined Immunodeficiency Disorders (CIDs) with susceptibility to infections. Combined immune deficiency disorders are usually commensurate with survival beyond infancy unlike Severe Combined Immune Deficiency (SCID) and are often associated with clinical features of a syndromic nature. Defective humoral and cellular immune responses result in susceptibility to a broad range of microbial infections. Although disease onset is usually in early childhood, mild defects may present in late childhood or even in adulthood. A precise diagnosis is imperative not only for determining management strategies, but also for providing accurate genetic counseling, including prenatal diagnosis, and also in deciding empiric treatment of infections upfront before investigation reports are available.

Insights into mucosal associated invariant T cell biology from human inborn errors of immunity.

Insights into mucosal associated invariant T cell biology from human inborn errors of immunity.

Elevated IgE from attenuated CARD11 signaling: lessons from atopic mice and humans.

CARD11 encodes a large scaffold protein responsible for integrating antigen-receptor engagement with downstream signaling to NF-kB and other outputs in lymphocytes. Over the past 10 years, several human-inborn errors of immunity have been linked to pathogenic CARD11 mutations. Most recently, severe atopic patients were discovered that carried heterozygous dominant-negative CARD11 mutations. Here, we review the mechanistic connections between attenuated CARD11 signaling, elevated IgE, and atopy, comparing and contrasting key insights from both human patients and murine models. Continued investigation of abnormal CARD11 signaling in both contexts should inform novel therapeutic strategies to combat allergic pathogenesis.

The 2022 Update of IUIS Phenotypical Classification for Human Inborn Errors of Immunity.

The International Union of Immunological Societies (IUIS) expert committee (EC) on Inborn Errors of Immunity (IEI) reports here the 2022 updated phenotypic classification, which accompanies and complements the most-recent genotypic classification. This phenotypic classification is aimed for clinicians at the bedside and focuses on clinical features and laboratory phenotypes of specific IEI. In this classification, 485 IEI underlying phenotypes as diverse as infection, malignancy, allergy, auto-immunity and auto-inflammation are described, including 55 novel monogenic defects and 1 autoimmune phenocopy. Therefore, all 485 diseases of the genetic classification are presented in this paper in the form of colored tables with essential clinical or immunological phenotype entries.

Human Inborn Errors of Immunity: 2022 Update on the Classification from the International Union of Immunological Societies Expert Committee

We report the updated classification of inborn errors of immunity, compiled by the International Union of Immunological Societies Expert Committee. This report documents the key clinical and laboratory features of 55 novel monogenic gene defects, and 1 phenocopy due to autoantibodies, that have either been discovered since the previous update (published January 2020) or were characterized earlier but have since been confirmed or expanded in subsequent studies. While variants in additional genes associated with immune diseases have been reported in the literature, this update includes only those that the committee assessed that reached the necessary threshold to represent novel inborn errors of immunity. There are now a total of 485 inborn errors of immunity. These advances in discovering the genetic causes of human immune diseases continue to significantly further our understanding of molecular, cellular, and immunological mechanisms of disease pathogenesis, thereby simultaneously enhancing immunological knowledge and improving patient diagnosis and management. This report is designed to serve as a resource for immunologists and geneticists pursuing the molecular diagnosis of individuals with heritable immunological disorders and for the scientific dissection of cellular and molecular mechanisms underlying monogenic and related human immune diseases.

Severe combined immunodeficiencies: Expanding the mutation spectrum in Turkey and identification of 12 novel variants.

Human Inborn Errors of Immunity (IEIs) are clinically and genetically heterogeneous group of diseases, with relatively mild clinical course or severe types that can be life-threatening. Severe combined immunodeficiency (SCID) is the most severe form of IEIs, which is caused by monogenic defects that impair the proliferation and function of T, B, and NK cells. According to the most recent report by the International Union of Immunological Societies (IUIS), SCID is caused by mutations in IL2RG, JAK3, FOXN1, CORO1A, PTPRC, CD3D, CD3E, CD247, ADA, AK2, NHEJ1, LIG4, PRKDC, DCLRE1C, RAG1 and RAG2 genes. The targeted next-generation sequencing (TNGS) workflow based on Ion AmpliSeq™ Primary Immune Deficiency Research Panel was designed for sequencing 264 IEI-related genes on Ion S5™ Sequencer. Herein, we present 21 disease-causing variants (12 novel) which were identified in 22 patients in eight different SCID genes. Next-generation sequencing allowed a rapid and an accurate diagnosis SCID patients.