Blended phenotypes exhibited by a patient may present a challenge to the establishment of diagnosis. In this study, we report a seven-year-old Murut girl with unusual features of Williams-Beuren syndrome (WBS), including recurrent infections and skin abscesses. Considering the possibility of a second genetic disorder, a mutation screening for genes associated with inborn errors of immunity (IEI) was conducted using whole exome sequencing (WES). Analysis of copy number variations (CNVs) from the exome data revealed a 1.53Mb heterozygous deletion on chromosome 7q11.23, corresponding to the known WBS. We also identified a biallelic loss of NCF1, which indicated autosomal recessive chronic granulomatous disease (CGD). Dihydrorhodamine (DHR) flow cytometric assay demonstrated abnormally low neutrophil oxidative burst activity. Coamplification of NCF1 and its pseudogenes identified a GT-deletion (ΔGT) at the start of exon 2 in NCF1 (NM_000265.7: c.75_76delGT: p.Tyr26Hisfs*26). Estimation of NCF1-to-NCF1 pseudogenes ratio using ΔGT and 20-bp gene scans affirmed nil copies of NCF1 in the patient. While the father had a normal ratio of 2:4, the mother had a ratio of 1:5, implicating the carrier of ΔGT-containing NCF1. Discovery of a 7q11.23 deletion involving one NCF1 allele and a ΔGT in the second NCF1 allele explained the coexistence of WBS and CGD in our patient. This study highlights the capability of WES to establish a molecular diagnosis for a case with blended phenotypes, enabling the provision of appropriate prophylactic treatment.
BACKGROUND: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency (PID) caused by a dysfunctional respiratory burst enzyme NADPH-oxidase. The concurrence of Klinefelter’s Syndrome (KS) and CGD would be extremely rare.
OBJECTIVE: We describe the study of a family where the youngest male child had X-linked CGD (X-CGD) while his older brother was both an X-CGD carrier and a Klinefelter.
METHODS: Flow cytometry was used to study respiratory burst and gp91-phox expression, while genetic investigation was done by RT-PCR, PCR and X-chromosome short tandem repeat (X-STR) analysis.
RESULTS: The Dihydrorhodamine (DHR) assay showed the patient’s neutrophils failed to produce a respiratory burst, while both the mother and an older brother showed a bimodal response. gp91-phox expression was absent in the patient’s neutrophils, and bimodal in the mother’s and brother’s neutrophils. The patient’s cDNA showed a C>T change at nucleotide 676 of the CYBB gene. The same change was seen in the patient’s gDNA, while the brother and mother were heterozygous, with C and T, in this position. The c.676C>T is a nonsense mutation that leads to premature termination of the gp91-phox protein. The brother karyotyped as 47, XXY and X chromosome analysis showed that he had inherited both his mother’s X chromosomes.
CONCLUSIONS: This study showed that the patient had gp91-phox deficient CGD while his older brother was a CGD carrier and a Klinefelter, who had inherited both his mother’s X chromosomes. This is the first report of such a concurrence in an individual, and argues for family members to be included in PID studies.
Key words: Chronic granulomatous disease, CYBB, gp91-phox, Klinefelter’s syndrome NADPHoxidase
BACKGROUND: The most common autosomal form of Chronic Granulomatous Disease, p47-phox deficient CGD, generally features a GT (deltaGT) deletion in the GTGT sequence at the start of exon 2 on the NCF-1 gene. This consistency is due to the coexistence of and the recombination between 2 homologous pseudogenes (psi s) and NCF-1. The GTGT: deltaGT ratio mirrors the NCF-I: NCF-1 psi ratio and is 2:4 in normal individuals.
OBJECTIVE: To determine the molecular basis of the Autosomal-CGD in a family with 2 children, a male and female, affected by the disease. The female patient suffered recurrent infection, retinitis pigmentosa and discoid lupus.
METHODS: Chemiluminescence (CL) was used to study the respiratory burst, while genetic analysis was done by RT-PCR, PCR, deltaGT and the 20bp gene scans.
RESULTS: The CL response of the patient was profoundly low. The patient's p47-phox band was absent in the RT-PCR for NADPH-oxidase component mRNAs. The deltaGT scan showed that the patient's GTGT: deltaGT ratio was 0:6, the parents' and the younger brother's was 1:5 and the younger sister's was 2:4. Examination of other NCF-1/ NCF-1 psi s differences showed that the father had a compound deltaGT allele ie. deltaGT-20bp, inherited by the patient, and that both parents had compound GTGT alleles with a single 30bp segment in intron 1.
CONCLUSIONS: The patient was a classic, homozygous deltaGT p47-phox deficient CGD with one allele harbouring a compound deltaGT-20bp gene. The deltaGT and 20bp gene scans offer a relatively simple and efficient means of defining a p47-phox deficient CGD patient.
Key words: Chronic Granulomatous Disease, Primary Immunodeficiency, NCF-1, p47-phox, NADPH-oxidas
Aqueous extract of Piper sarmentosum (AEPS) is known to possess antioxidant and anti-atherosclerotic activities but the mechanism responsible for it remains unclear. In early part of atherosclerosis, nuclear factor-kappa B (NF-κB) induces the expression of cellular adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1) and E-selectin. NADPH oxidase 4 (Nox4) is the predominant source of superoxide in the endothelial cells whereas superoxide dismutase 1 (SOD1), catalase (CAT) and glutathione peroxidase (GPx) are the antioxidant enzymes responsible for inactivating reactive oxygen species. The present study aimed to investigate the effects of AEPS on the gene expression of NF-κB, VCAM-1, ICAM-1, E-selectin, Nox4, SOD1, CAT and GPx in cultured human umbilical vein endothelial cells (HUVECs).