Clinical and genetic features of the patients with X-Linked agammaglobulinemia from Turkey: Single-centre experience.

X-linked agammaglobulinemia is a primary immunodeficiency disorder resulting from BTK gene mutations. There are many studies in the literature suggesting contradictory ideas about phenotype-genotype correlation. The aim of this study was to identify the mutations and clinical findings of patients with XLA in Turkey, to determine long-term complications related to the disease and to analyse the phenotype-genotype correlation. Thirty-two patients with XLA diagnosed between 1985 and 2016 in Pediatric Immunology Department of Hacettepe University Ihsan Dogramaci Children's Hospital were investigated. A clinical survey including clinical features of the patients was completed, and thirty-two patients from 26 different families were included in the study. Getting early diagnosis and regular assessment with imaging techniques seem to be the most important issues for improving the health status of the patients with XLA. Early molecular analysis gives chance for definitive diagnosis and genetic counselling, but not for predicting the clinical severity and prognosis.

Chronic granulomatous disease presenting with hypogammaglobulinemia.

Chronic granulomatous disease (CGD) is a primary immunodeficiency disorder caused by inherited defects in the nicotinamide adenine dinucleotide phosphate oxidase complex. The neutrophils of patient with CGD can ingest bacteria normally, but the oxidative processes that lead to superoxide anion formation, hydrogen peroxide production, nonoxidative pathway activation, and bacterial killing are impaired. Serious infections result from microorganisms that produce catalase. Immunoglobulin levels of patients with CGD are usually normal or elevated. We describe a patient with CGD associated with hypogammaglobulinemia, an unusual co-occurrence.

H2AX gene does not have a modifier effect on ataxia-telangiectasia phenotype.

Ataxia-telangiectasia (AT) is a complex disorder characterized by progressive neurodegeneration, immunodeficiency, hypersensitivity to DNA damaging agents and cancer predisposition. Clinical heterogeneity is observed even among the affected siblings with AT. Mutations of the ataxia-telangiectasia mutated (ATM) gene are responsible for AT. H2AX, an essential histone protein, is phosphorylated by ATM in response to double-strand breaks, and H2AX-deficient mice share some clinical and laboratory findings with AT. Therefore, we sought a possible modifier effect of H2AX gene on various clinical features in a group of patients with AT and healthy controls. We performed sequence analysis of H2AX gene in 81 patients with AT, and in 51 of them, we analysed methylation. We examined H2AX gene expression in 25 patients. We investigated 48 healthy individuals as a control group. We did not detect any mutation or sequence variation in the H2AX gene, or any altered methylation pattern in any of the patients. Although H2AX gene expression was markedly increased (2.5- to 11.8-fold) in five of 25 patients, and slightly increased (1.5- to 2.4-fold) in four patients, the correlations between H2AX gene expression and the evaluated clinical features of the patients were not significant. Other potential modifier genes that might be scrutinized in AT patients include p53, 53BP1 and TIP60, as well as the genes that effect mitochondrial function and the oxidative response.

Four different NCF2 mutations in six families from Turkey and an overview of NCF2 gene mutations.

BACKGROUND: One of the rarest forms of autosomal recessive chronic granulomatous disease (AR-CGD) is attributable to mutations in the NCF2 gene, which encodes the polypeptide p67(phox), a key cytoplasmic protein in the phagocyte NADPH oxidase system. NCF2 is localized on chromosome 1q25, encompasses 40 kb and contains 16 exons. MATERIALS AND METHODS: We report here the clinical and molecular characterization of six patients with CGD from six consanguineous Turkish families. The ages of the five female patients were between 3 and 22 years and a male patient was 2 years old; all patients showed clear clinical symptoms of CGD. RESULTS: The mothers of the patients did not show a bimodal histogram pattern specific for X-CGD in the dihydrorhodamine-1,2,3 (DHR) assay. Moreover, p67(phox) protein expression was not detectable using flow cytometric analysis of the patients' neutrophils except in those from patient 6, which had a diminished expression. Mutation analysis of NCF2 revealed four different homozygous mutations: a novel nonsense mutation in exon 3 c.229C>T, p.Arg77X; a novel missense mutation in exon 4 c.279C>G, p.Asp93Glu; a nonsense mutation in exon 4 c.304C>T, p.Arg102X; and a novel missense mutation in exon 6 c.605C>T, p.Ala202Val. The parents were found to be heterozygotes for these mutations. CONCLUSIONS: The prevalence of NCF2 mutant families is approximately 15% in our series of 40 CGD families. This high incidence of A67 CGD in Turkey is undoubtedly caused by the high incidence of consanguineous marriages. We found three new mutations in NCF2 and one previously described. These are presented together with an overview of all NCF2 mutations now known.

Six different CYBA mutations including three novel mutations in ten families from Turkey, resulting in autosomal recessive chronic granulomatous disease.

BACKGROUND: One of the rarest forms of autosomal recessive chronic granulomatous disease (AR-CGD) is attributable to mutations in the CYBA gene, which encodes the alpha polypeptide of cytochrome b(558), (also known as p22-phox), a key transmembrane protein in the phagocyte NADPH oxidase system. This gene is localized on chromosome 16q24, encompasses 8.5 kb and contains six exons. MATERIALS AND METHODS: We report here the clinical and molecular characterization of 12 AR-CGD patients from 10 consanguineous, unrelated Turkish families with clinical CGD and positive family history. The ages of the six male and six female patients were between 1and 18 years. Before mutation analysis, subgroup analysis of patients was made by flow cytometry with antibodies against NADPH-oxidase components and with the DHR assay (flow cytometric assay of NADPH oxidase activity in leucocytes). RESULTS: Mutation analysis of CYBA showed six different mutations: a frameshift insertion in exon 3 (C after C166); a missense mutation in exon 2 (p.Gly24Arg), a splice-site deletion in intron 1 (4-bp deletion +4_+7 AGTG), a novel nonsense mutation in exon 6 (p.Cys113X), a novel large deletion of exons 3-6 and a novel 1-bp deletion in exon 6 (c.408delC). All mutations were present in homozygous form and all parents investigated were found to be heterozygotes for these mutations. CONCLUSIONS: In our series of 40 CGD families, approximately 25% of the families have p22-phox defects, with six different mutations, including three novel mutations. The high rate of consanguineous marriages seems to be the underlying aetiology.