Inherited p40^{phox} deficiency differs from classic chronic granulomatous disease

Biallelic loss-of-function (LOF) mutations of the NCF4 gene, encoding the p40^{phox} subunit of the phagocyte NADPH oxidase, have been described in only 1 patient. We report on 24 p40^{phox}-deficient patients from 12 additional families in 8 countries. These patients display 8 different in-frame or out-of-frame mutations of NCF4 that are homozygous in 11 of the families and compound heterozygous in another. When overexpressed in NB4 neutrophil-like cells and EBV-transformed B cells in vitro, the mutant alleles were found to be LOF, with the exception of the p.R58C and c.120_134del alleles, which were hypomorphic. Particle-induced NADPH oxidase activity was severely impaired in the patients’ neutrophils, whereas PMA-induced dihydrorhodamine-1,2,3 (DHR) oxidation, which is widely used as a diagnostic test for chronic granulomatous disease (CGD), was normal or mildly impaired in the patients. Moreover, the NADPH oxidase activity of EBV-transformed B cells was also severely impaired, whereas that of mononuclear phagocytes was normal. Finally, the killing of Candida albicans and Aspergillus fumigatus hyphae by neutrophils was conserved in these patients, unlike in patients with CGD. The patients suffer from hyperinflammation and peripheral infections, but they do not have any of the invasive bacterial or fungal infections seen in CGD. Inherited p40^{phox} deficiency underlies a distinctive condition, resembling a mild, atypical form of CGD

Inherited p40phox deficiency differs from classic chronic granulomatous disease

Biallelic loss-of-function (LOF) mutations of the NCF4 gene, encoding the p40phox subunit of the phagocyte NADPH oxidase, have been described in only 1 patient. We report on 24 p40phox-deficient patients from 12 additional families in 8 countries. These patients display 8 different in-frame or out-of-frame mutations of NCF4 that are homozygous in 11 of the families and compound heterozygous in another. When overexpressed in NB4 neutrophil-like cells and EBV-transformed B cells in vitro, the mutant alleles were found to be LOF, with the exception of the p.R58C and c.120_134del alleles, which were hypomorphic. Particle-induced NADPH oxidase activity was severely impaired in the patients' neutrophils, whereas PMA-induced dihydrorhodamine-1,2,3 (DHR) oxidation, which is widely used as a diagnostic test for chronic granulomatous disease (CGD), was normal or mildly impaired in the patients. Moreover, the NADPH oxidase activity of EBV-transformed B cells was also severely impaired, whereas that of mononuclear phagocytes was normal. Finally, the killing of Candida albicans and Aspergillus fumigatus hyphae by neutrophils was conserved in these patients, unlike in patients with CGD. The patients suffer from hyperinflammation and peripheral infections, but they do not have any of the invasive bacterial or fungal infections seen in CGD. Inherited p40phox deficiency underlies a distinctive condition, resembling a mild, atypical form of CGD.info:eu-repo/semantics/publishedVersio

Loss of function NFKB1 variants are the most common monogenic cause of CVID in Europeans.

BACKGROUND: The genetic etiology of primary immunodeficiency disease (PID) carries prognostic information. OBJECTIVE: We conducted a whole-genome sequencing study assessing a large proportion of the NIHR-BioResource - Rare Disease cohort. METHODS: In the predominantly European study population of principally sporadic unrelated PID cases (n=846), a novel Bayesian method identified NFKB1 as one most strongly associated with PID, and the association was explained by 16 novel heterozygous truncating, missense and gene deletion variants. This accounted for 4% of common variable immunodeficiency (CVID) cases (n=390) in the cohort. Amino-acid substitutions predicted to be pathogenic were assessed by analysis of structural protein data. Immunophenotyping, immunoblotting and ex vivo stimulation of lymphocytes determined the functional effects of these variants. Detailed clinical and pedigree information was collected for genotype-phenotype co-segregation analyses. RESULTS: Both sporadic and familial cases demonstrated evidence of the non-infective complications of CVID, including massive lymphadenopathy (24%), unexplained splenomegaly (48%) and autoimmune disease (48%), features prior studies correlate with worse clinical prognosis. Although partial penetrance of clinical symptoms was noted in certain pedigrees, all carriers have a deficiency in B lymphocyte differentiation. Detailed assessment of B lymphocyte numbers, phenotype and function identifies the presence of a raised CD21lowB cell population: combined with identification of the disease-causing variant, this distinguishes between healthy individuals, asymptomatic carriers and clinically affected cases. CONCLUSION: We show that heterozygous loss-of-function variants in NFKB1 are the most common known monogenic cause of CVID that results in a temporally progressive defect in the formation of immunoglobulin-producing B cells.This study was supported by The National Institute for Health Research England (grant number RG65966), and by the Center of Immunodeficiencies Amsterdam (CIDA). JET is supported by an MRC Clinician Scientist Fellowship (MR/L006197/1). AJT is supported by both the Wellcome Trust (104807/Z/14/Z) and by the National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London. EO receives personal fees from CSL Behring and MSD

A Spoken-Language Intervention for School-Aged Boys With Fragile X Syndrome

Using a single case design, a parent-mediated spoken language intervention was delivered to three mothers and their school-aged sons with fragile X syndrome, the leading inherited cause of intellectual disability. The intervention was embedded in the context of shared story-telling using wordless picture books and targeted three empirically-derived language support strategies. All sessions were implemented via distance video-teleconferencing. Parent education sessions were followed by 12 weekly clinician coaching and feedback sessions. Data was collected weekly during independent homework and clinician observation sessions. Relative to baseline, mothers increased their use of targeted strategies and dyads increased the frequency and duration of story-related talking. Generalized effects of the intervention on lexical diversity and grammatical complexity were observed. Implications for practice are discussed

Inherited p40(phox) deficiency differs from classic chronic granulomatous disease

Biallelic loss-of-function (LOF) mutations of the NCF4 gene, encoding the p40phox subunit of the phagocyte NADPH oxidase, have been described in only 1 patient. We report on 24 p40phox-deficient patients from 12 additional families in 8 countries. These patients display 8 different in-frame or out-of-frame mutations of NCF4 that are homozygous in 11 of the families and compound heterozygous in another. When overexpressed in NB4 neutrophil-like cells and EBV-transformed B cells in vitro, the mutant alleles were found to be LOF, with the exception of the p.R58C and c.120_134del alleles, which were hypomorphic. Particle-induced NADPH oxidase activity was severely impaired in the patients' neutrophils, whereas PMA-induced dihydrorhodamine-1,2,3 (DHR) oxidation, which is widely used as a diagnostic test for chronic granulomatous disease (CGD), was normal or mildly impaired in the patients. Moreover, the NADPH oxidase activity of EBV-transformed B cells was also severely impaired, whereas that of mononuclear phagocytes was normal. Finally, the killing of Candida albicans and Aspergillus fumigatus hyphae by neutrophils was conserved in these patients, unlike in patients with CGD. The patients suffer from hyperinflammation and peripheral infections, but they do not have any of the invasive bacterial or fungal infections seen in CGD. Inherited p40phox deficiency underlies a distinctive condition, resembling a mild, atypical form of CGD.status: publishe