ABSTRACT:Leukopoiesis is lethally arrested in mice lacking the master transcriptional regulator PU.1. Depending on the animal model, subtotal PU.1 loss either induces acute myeloid leukemia or arrests early B-cell and dendritic-cell development. Although humans with absolute PU.1 deficiency have not been reported, a small cadre of congenital agammaglobulinemia patients with sporadic, inborn PU.1 haploinsufficiency was recently described. To better estimate the penetrance, clinical complications, immunophenotypic features, and malignancy risks of PU.1-mutated agammaglobulinemia (PU.MA), a collection of 134 novel or rare PU.1 variants from publicly available databases, institutional cohorts, previously published reports, and unsolved agammaglobulinemia cases were functionally analyzed. In total, 25 loss-of-function (LOF) variants were identified in 33 heterozygous carriers from 21 kindreds across 13 nations. Of individuals harboring LOF PU.1 variants, 22 were agammaglobulinemic, 5 displayed antibody deficiencies, and 6 were unaffected, indicating an estimated disease penetrance of 81.8% with variable expressivity. In a cluster of patients, disease onset was delayed, sometimes into adulthood. All LOF variants conveyed effects via haploinsufficiency, either by destabilizing PU.1, impeding nuclear localization, or directly interfering with transcription. PU.MA patient immunophenotypes consistently demonstrated B-cell, conventional dendritic-cell, and plasmacytoid dendritic-cell deficiencies. Associated infectious and noninfectious symptoms hewed closely to X-linked agammaglobulinemia and not monogenic dendritic-cell deficiencies. No carriers of LOF PU.1 variants experienced hematologic malignancies. Collectively, in vitro and clinical data indicate heterozygous LOF PU.1 variants undermine humoral immunity but do not convey strong leukemic risks.

Ataxia-Telangiectasia (A-T) is a neurodegenerative disease caused by bi-allelic mutations in the Ataxia-Telangiectasia-Mutated (ATM) gene. Complete lack of ATM activity leads to severe A-T and mutations allowing for residual activity cause a milder phenotype, termed variant A-T. There are only sparse data on the variability in phenotypes of variant A-T patients carrying the same mutations. A retrospective study of 15 patients with variant A-T, all double homozygous for the same mutations was conducted. The age of first symptom ranged from 4-180 months, including: truncal ataxia at <18 months of age in 9 patients, ataxia and instability only during fever in one patient, dystonia in one patient and malignancy in 4 patients. Global developmental delay and occulo-motor apraxia were recorded in 4/14 patients. Variant A-T patients with the same mutations in ATM, have variable phenotypes. Environmental, epigenetic, and post translational factors are likely to play a role in creation of the phenotype in variant A-T patients.

Patients with primary immunodeficiency and atopy were found to have genetic faults in various components of the IL-6 pathway.1,2 IL-6 has a wide range of biological actions and target tissues.3 The cell-surface receptor for IL-6 is composed of 2 transmembrane chains: a ligand binding IL-6 receptor (IL-6R) and the signal-transducing gp130 (IL6ST) coreceptor. Binding of IL-6 to IL-6R triggers association with gp130 and formation of a high-affinity IL-6 binding site, initiating signal transduction.

The nuclease Artemis is a enzyme for V(D)J recombination allowing for the creation of T and B lymphocytes as well as for the repair of radiation-induced DNA double strand breaks encoded by the DCLRE1C gene. Artemis-null mutations are a known cause of severe combined immunodeficiencies (SCIDs) with radiosensitivity. Hypomorphic mutations in Artemis have been reported to cause a "leaky SCID"" phenotype, typically with hypogammaglobulinemia. We present four patients, all harboring the same unique hypomorphic mutation in the DCLRE1C gene, an 8-base pair insertion (c.1299_1306dup, p.Cys436*) presenting with a relatively mild phenotype including pulmonary infectious EBV-related lymphoproliferative diseases, an autoimmune phenomenon. Non-typical findings of IgG hypergammaglobulinemia accompanied by IgA and IgE deficiency were recorded in all patients. The typical viral, fungal, and opportunistic infections were absent, and patients reached a relatively old age.

Neutrophil chemotactic defects have been reported previously in patients with hyper-IgE syndrome. Bi-allelic mutations in dedicator of cytokinesis 8 (DOCK8) gene usually cause an autosomal recessive hyper-IgE syndrome phenotype. Data are lacking about expression of DOCK8 protein in neutrophils or the possible role of DOCK8 in neutrophil function. We sought to determine if DOCK8 protein is expressed in neutrophils and if DOCK8 plays a role in neutrophil function. The expression of DOCK8 protein was assessed in neutrophils from healthy volunteers with and without activators. Neutrophil chemotaxis, phagocytosis and superoxide generation were studied in neutrophils from DOCK8-deficient patients compared to neutrophils from healthy controls before and after stimulation with activators: phorbol 12-myristate 13-acetate (PMA) or N-Formylmethionyl-leucyl-phenylalanine (fMLP). DOCK8 protein is expressed in resting neutrophils from healthy controls, with a significant increase in DOCK8 expression after stimulation. Neutrophil functions were assessed in 6 DOCK8-deficient patients. All patients had the same non-sense mutation (c.C5134A, p.S1711X). Normal chemotaxis was recorded in 4/6 patients while a mild to moderate chemotaxis defect was recorded in 2/6. Superoxide generation was mainly normal in neutrophils from all six patients and phagocytosis was normal in five patients tested. We conclude that DOCK8 protein is expressed in resting human neutrophils and DOCK8 expression is increased after stimulation with either PMA or fMLP. Most patients with a disease-causing mutation in DOCK8 have normal neutrophil functions, while a minority showed a mild to moderate chemotactic defect.

Chronic granulomatous disease is a primary immunodeficiency disease caused by a genetic mutation in any of the 5 genes encoding the different components of the Nicotinamide Adenine Dinucleotide Phosphate reduced (NADPH)-Oxidase enzyme complex. Since primary immunodeficiency diseases are considered to be rare diseases, the genetic diagnosis of a certain primary immunodeficiency leads to the reasonable assumption that all patients with the same disease within the same family will have the same genetic mutation. We report 2 patients with chronic granulomatous disease from the same extended consanguineous family who had different genetic causes of their disease. Therefore, it is crucial to obtain a definitive genetic diagnosis of primary immunodeficiency disease even in patients from the same family, where the same genetic diagnosis is presumed to be the cause of the disease. Statement of novelty: Genetic causes of chronic granulomatous disease may be different in patients from the same family.

Neutrophil chemotactic defects have been reported in patients with Hyper IgE syndrome. Mutations in dedicator of cytokinesis 8 gene (DOCK8) gene cause a combined immunodeficiency that can be diagnosed as a hyper IgE syndrome and DOCK8 plays a role in reorganization of the F-actin cytoskeleton in NK and dentritic cells. However, data are lacking about the possible role of DOCK8 in neutrophil function. The expression of DOCK8 protein was assessed in neutrophils from healthy volunteers before and after stimulation with neutrophil activators: phorbol 12-myristate 13-acetate (PMA) or N-Formylmethionyl-leucyl-phenylalanine (fMLP). Neutrophil functions, including chemotaxis, phagocytosis and superoxide generation were studied in neutrophils from DOCK8 deficient patients compared to neutrophils from healthy controls. DOCK8 protein was found to be expressed in resting neutrophils with a significant up-regulation of DOCK8 after stimulation with PMA or fMLP. Neutrophil functions were assessed in 6 patients. All patients were homozygotes for the same mutation in the DOCK8 gene (c.C5134A, p.S1711X) causing a premature stop codon mutation in DOCK8. Lack of expression of the DOCK8 protein in T cells was revealed by flow-cytometry in one patient. A mild to moderate neutrophil chemotaxis defect was recorded in neutrophils from 2/6 (33.3%) of the patients while phagocytosis and superoxide generation were normal. We conclude that the DOCK8 protein is expressed in resting human neutrophils and is upregulated after stimulation with PMA or fMLP. Most patients with a disease-causing mutation in DOCK8 have normal neutrophil function, while a minority showed a mild to moderate chemotactic defect.

Primary immunodeficiency diseases are considered to be rare diseases; however, data on the exact birth incidences of these diseases are sparse. Southern Israel is inhabited by two major populations: a relatively non-consanguineous Jewish population and a highly consanguineous Muslim Bedouin population. We sought to calculate the incidences of typically severe primary immunodeficiency diseases and compare the incidences in these populations.

Mutations in the dedicator of cytokinesis 8 (DOCK8) gene cause a combined immunodeficiency usually diagnosed as autosomal recessive hyper IgE syndrome. We sought to reveal the varying manifestations in patients with a unique mutation in DOCK8 gene by a retrospective medical record review. Ten patients from five consanguineous families and three tribes were included. Seven patients were homozygous for the c.C5134A, p.S1711X mutation, and the remaining three patients were their siblings manifesting hyper IgE syndrome features without a genetic diagnosis. Prior to the genetic diagnosis, the clinical diagnosis was “hyper IgE syndrome” in six patients and “anti-pneumococcal antibody deficiency,” “recurrent pneumonia with bronchiectasis,” and “asthma with hypereosinophilic syndrome” each diagnosed once. One additional patient was diagnosed due to family history. The age of presentation varied from 1 to 16 months. Eczema was diagnosed in all patients, food allergies in three, and severe herpes keratitis or malignancy or autoimmunity in two patients. Elevated IgE was recorded in nine patients; however, in six patients, the initial serum IgE concentration was equal to or less than three times the normal concentration for age, and in these patients, the median age at IgE evaluation was 7.5 months compared with 21.5 months in patients with an initial IgE concentration above three times the normal concentration for age (P = 0.067). The spectrum of disease manifestations in patients with a unique mutation in DOCK8 is variable. The genotype-phenotype correlations may be modified by genetic and/or epigenetic modifiers beyond the monogenic effect. Younger patients tend to have lower IgE concentrations at the initial measurement of IgE.

Primary immunodeficiences are often accompanied by autoimmune phenomena. IL-12 receptor deficiency is a well characterized primary immunodeficiency that leads to propensity to intracellular infections mainly with mycobacteria and Salmonella. We report on two patients with IL-12 receptor β1 deficiency that presented with autoimmune manifestations and photosensitivity dermatitis and describe possible pathogenetic mechanisms leading to development of clinically significant autoimmune phenomena.

Chronic granulomatous disease is a primary immunodeficiency caused by impaired neutrophil production of reactive oxygen species. Non-infectious colitis is common in chronic granulomatous disease, and high levels of antimicrobial antibodies that are associated with Crohn's disease are common even without colitis. Fecal calprotectin concentration is a marker for intestinal inflammation. We sought to determine whether subclinical intestinal inflammation occurs in asymptomatic chronic granulomatous disease patients. Asymptomatic chronic granulomatous disease patients without overt gastrointestinal symptoms suggestive of colitis at the time of enrollment were studied for fecal calprotectin concentration, antibodies associated with Crohn's disease and systemic inflammatory markers. Eight patients were included, aged 54-176 months. In 7/8 (87.5 %) fecal calprotectin concentration was normal (<50) and elevated (137 mg/kg) in only one patient. This patient later developed colitis. In 7/8 (87.5 %) anti-Saccharomyces cerevisiae antibody was positive. C-reactive protein, albumin, complete blood count and p-anti-neutrophil cytoplasmic antibody were normal in all 8 patients. Subclinical colitis is not evident in most asymptomatic chronic granulomatous disease patients; however, in some patients, fecal calprotectin concentration may be elevated, possibly indicating the presence of subclinical colitis and predicting the occurrence of clinically relevant colitis. Serum anti-Saccharomyces cerevisiae antibody concentrations do not seem to correlate with fecal calprotectin concentration in asymptomatic chronic granulomatous disease patients.

Background: Familial hemophagocytic lymphohistiocytosis (FHL) is a rare, genetic, immune dysregulation disorder of aberrant hyperactivation of lymphocytes causing inflammation and hemophagocytosis. We report on a 3-month old male who was evaluated for the possibility of FHL because of a positive family history. The patient was asymptomatic; however, levels of the soluble interleukin 2 (IL-2) receptor were elevated and the quantity and function of the natural killer (NK) cells were severely decreased. Methods: Purification of NK cells and evaluation of the cytotoxicity and IFNγ/TNFα secretion of NK cells after IL-2 activation relative to the patient's family members. Results: The patient's NK specific lysis was enhanced compared with his mother, and it was slightly higher than his sister. The IFNγ and TNFα secretion by the patient's NK cells after challenge with target 721 cells or anti-natural cytotoxicity receptors (NKp30 and NKp44) antibodies showed levels that are close to the mother's and sister's NK secretion levels. Owing to a low yield of NK cells from the patient's father the results for his NK cells are incomplete. The patient did not undergo HSCT and continued to be followed. He is now 7 years old and thriving without signs of FHL. His last examination was in August 2012 for functionality of isolated NK cells. The results showed normal cytotoxicity, cytokine secretion, and CD107a up-regulation to the NK cell surface. Conclusion: We propose that NK function assessment in patients with presumed FHL should be performed on isolated NK cell populations. This practice may reduce the number of false-negative results in NK function assays. Statement of novelty: In this case report we show that functional assessment of unpurified NK cells could lead to a false-negative assessment in 1 of the parameters in FHL. Assessment of NK function without NK purification may lead to an erroneous diagnosis of poor NK function.

The role of the Bruton tyrosine kinase (Btk) protein in neutrophil function has been evaluated using neutrophils from healthy volunteers after incubation with a Btk inhibitor, leflunomide metabolite analog (LFM-A13), suggesting an important role for Btk in neutrophil function. We sought to determine the role of Btk protein on neutrophil superoxide generation and chemotaxis stimulated by N-formyl-methionine-leucine-phenylalanine (fMLP).

BACKGROUND:Congenital insensitivity to pain with anhidrosis (CIPA) is a congenital autonomic sensory neuropathy. In southern Israel, there are many patients with this disease. We here tried to characterize the different infections acquired by children with CIPA.METHODS:We collected all the available data about CIPA patients in southern Israel in the year 1991-2005, including the lesion types, area in the body where the infection occurs, and the treatment given.RESULTS:The current study included 30 children with CIPA, out of 44 known CIPA patients in southern Israel (68.2%). A total of 382 different episodes of infections, fever, orthopedic lesions, and jaw and mouth lesions led our patients to our outpatient clinic or resulted in hospitalization.CONCLUSION:We found that children with CIPA mainly have infections of the skin and skeleton, and that the most frequent pathogen is Staphylococcus aureus. We also found that a fair amount of these pathogens are resistant to conventional treatment regimens.

BACKROUND: Congenital insensitivity to pain (CIP) is a rare condition in which patients have no pain perception and anosmia but are otherwise essentially normal (OMIM 243000). The recent discovery of the genetic defects underlying 3 monogenic pain disorders has provided additional and important insights about some components of human pain. Genetic studies in families demonstrating recessively inherited channelopathy-associated insensitivity to pain have identified nonsense mutations that result in truncation of the voltage-gated sodium channel type IX subunit (SCN9A), a 113.5-kb gene comprising coding 26 exons. Here we describe a patient with CIP with a new mutation in SCN9A not described yet. METHODS: All exons were sequenced. RESULT: All 26 coding exons were sequenced and two changes were identified in homozygosity in exon 10: c.1126 A > C causing K376Q and c.1124delG causing p.G375Afs* frame shift. CONCLUSION: We report a novel, loss-of-function mutation in homozygosity that causes congenital insensitivity to pain and provide a comprehensive clinical description of the patient. This contributes to the clinical and neurophysiological characteristic of the sodium channel Na(v)1.7 channelopathy and expand our genetic knowledge which might provide more accurate and comprehensive clinical electrophysiological and genetic information.

Congenital insensitivity to pain with anhidrosis is a rare disease affecting the nervous system. The patients present with unexplained fever from poor thermoregulation and inability to sweat. Because of the indifference to pain, they manifest frequent traumatic and infectious injuries. Evaluations of these patients include investigation of the hypotonia and weakness evident in this group of patients. We report four patients presenting characteristic features of congenital insensitivity to pain with anhidrosis who carry an identical mutation in the TRK-A gene and who underwent nerve and skeletal muscle biopsies. All four patients had normal sensory and motor conduction studies but lacked sympathetic skin responses. Examination of the skeletal muscles biopsies obtained from two of the patients disclosed marked myopathic changes. The muscle biopsy of a third patient showed mild variation in muscle fibers and the fourth patient's muscle biopsy showed type 1 fiber predominance. Electron microscopy studies revealed remarkable decrease in the number of small caliber-myelinated and unmyelinated nerve fibers. We assume that the variable histological findings in the muscle biopsies of these patients reflect a variation in congenital insensitivity to pain with anhidrosis patients that is not related to their genetic mutation.

IL-12Rβ1 deficiency is an autosomal recessive disorder characterized by predisposition to recurrent and/or severe infections caused by otherwise poorly pathogenic mycobacteria and salmonella. IL-12Rβ1 is a receptor chain of both the IL-12 and the IL-23 receptor and deficiency of IL-12Rβ1 thus abolishes both IL-12 and IL-23 signaling. IL-12Rβ1 deficiency is caused by bi-allelic mutations in the IL12RB1 gene. Mutations resulting in premature stop codons, such as nonsense, frame shift, and splice site mutations, represent the majority of IL-12Rβ1 deficiency causing mutations (66%; 46/70). Also every other morbid mutation completely inactivates the IL-12Rβ1 protein. In addition to disease-causing mutations, rare and common variations with unknown functional effect have been reported in IL12RB1. All these variants have been deposited in the online IL12RB1 variation database (www.LOVD.nl/IL12RB1). In this article, we review the function of IL-12Rβ1 and molecular genetics of human IL12RB1.

Congenital insensitivity to pain with anhidrosis (CIPA) is a rare hereditary sensory and autonomic neuropathy (HSAN) characterized by pain, self-mutilating behaviour, anhidrosis and recurrent hyperthermia. CIPA has a multisystem involvement, including fractures of the extremities with slow healing, immunologic abnormalities, and a chronic inflammatory state. The mandible is reported to have a higher incidence of osteomyelitis, though mandibular fracture among CIPA patients, is very rare, with to our knowledge no reports in children. A case of pathological fracture of the mandible in a 6-year-old child with CIPA treated by ORIF is reported. In contrast to the slow healing reported in long bones, the mandible healed very quickly, possibly indicating that the osteoporotic mandible in this group of patients is different from that seen in the elderly. Furthermore, the standard ORIF technique can be safely used in this rare group.

Chronic granulomatous disease (CGD) is an immune deficiency syndrome caused by defects in the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, the enzyme that generates reactive oxygen species (ROS) in phagocytizing leukocytes. This study evaluates the NADPH oxidase capacity in two X-linked CGD patients with mutations in gp91phox that alter the regions in this membrane-bound NADPH oxidase component involved in docking of the cytosolic component p47phox.

Objective: To determine the frequency of mandibular osteomyelitis (OM) in patients with congenital insensitivity to pain with anhidrosis (CIPA) and to relate its appearance to possible risk factors.Methods: The records of 33 patients were reviewed for data concerning events of jaw OM, oral trauma, maxillofacial interventions, or OM of long bones.Results: Eighteen percent of the patients had mandibular OM. Of the six patients, preceding oral laceration was documented in one and tooth extraction in two. Seventy percent of the patients had OM of the limbs, but only 15% overlapped, having both jaw and limb OM. Half of the patients with mandibular OM had also OM of the limbs during the following year. There seems to be a correlation between high frequency of limb OM (at least 5 events per patient) and appearance of mandibular OM.Conclusion: The incidence of mandibular OM is very high among patients with CIPA and can result in pathologic fracture and the need for open reduction and internal fixation. The reason for this phenomenon is presently not clear. Preventive and therapeutic strategy for CIPA patients should be undertaken to minimize this severe complication. (C) 2011 Elsevier Ireland Ltd. All rights reserved.