Genetic Susceptibility in Family Members of Egyptian Hepatitis C Virus Infected Patients: Role of Interleukin-12 B Gene Polymorphism

AIM

The research was conducted to study 1188 A\C polymorphism of Interleukin (IL)-12B gene for C/C, A/C and A/A genotypes in families of Hepatitis C virus (HCV) infected patients in Egypt.

METHODS

Three hundreds HCV patients, 860 family members and 100 healthy subjects were studied. All family members were screened for HCV antibodies by enzyme-linked immunosorbent assay (ELISA). Positive cases were examined using Real-Time polymerase chain reaction (PCR) to confirm the presence of HCV ribonucleic acid (RNA) and detect the viral load. Molecular study of IL-12B gene was carried out on all patients, family members and controls using PCR and restriction enzyme analysis.

RESULTS

HCV infection was confirmed in 10.6% of family members. The distribution of IL-12B gene polymorphism in patients was 2.3%, 45.7% and 52% for C/C, A/C and A/A genotypes respectively, in infected family members was 3.3%, 41.7%, 55%, in noninfected family members was 4.5%, 43.5% and 52% for C/C, A/C and A/A genotypes respectively and in control was 5%, 36% and 59% for C/C, A/C and A/A genotypes respectively. The frequency of the C/C, A/C and A/A genotype was not significantly different between the studied groups.

CONCLUSION

IL-12B gene polymorphism has no role in intrafamilial susceptibility of HCV transmission. The distribution of the functional 1188 A\C polymorphism of Interleukin (IL)-12B gene for C/C, A/C and A/A genotypes was not significantly different among the studied groups.

Endothelial nitric oxide synthase gene (T786C and G894T) polymorphisms in Egyptian patients with type 2 diabetes

BACKGROUND

Genetic factors play important role in the development of type 2 diabetes and diabetic nephropathy. Endothelial nitric oxide synthase (eNOS) gene is responsible for the bioavailability of nitric oxide and endothelial function.

AIM

To assess the association of the endothelial nitric oxide synthase (eNOS) (T786C and G894T) single nucleotide polymorphisms with Egyptian type 2 diabetes mellitus and diabetic nephropathy.

PATIENTS AND METHODS

A total of 200 type 2 diabetic patients and 100 apparently healthy volunteers as controls were included in the study. They were subjected to clinical examination and laboratory tests: fasting blood glucose, HBA1C, lipid profile, serum creatinine, blood urea and albumin creatinine ratio (ACR). Assessment of the T786C and G894T polymorphisms in the eNOS gene was done using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

There was no significant difference in distribution of eNOS T-786C polymorphism between patients and controls; TT genotype of eNOS G894T was more frequent in diabetic patients with and without albuminuria compared to controls. Patients were divided into 3 groups according to ACR. Normoalbuminuria: 37 patients with ACR ≤ 30 mg/g, microalbuminuria: 96 patients with ACR > 30 mg/g and ≤ 300 mg/g, and macroalbuminuria: 67 patients with ACR > 300 mg/g. There was no significant difference in genotype distribution of eNOS T-786C between the 3 groups of diabetic patients. The prevalence of TT genotype of eNOS G894T was higher in microalbuminuria patients compared to other groups.

CONCLUSION

eNOS G894T variant may increase risk of type 2 diabetes with lack of association between eNOS T786C, eNOS G894T and DN in Egyptians.

Aicardi-Goutières syndrome: unusual neuro-radiological manifestations

Aicardi-Goutières syndrome (AGS) is one of the expanding group of inherited congenital infection like syndromes. Here, we describe the detailed clinical and imaging findings of two sibs with AGS. Each shows scattered periventricular intracranial calcifications, severe global delay, seizures, microcephaly and spasticity. Interestingly, chilblains were observed in the two sisters as well as their parents and a paternal uncle. The brain MRI of the older sister showed marked ventricular dilatation as a result of unusual associated porencephalic cysts. Unexpectedly, unilateral cerebellar hypoplasia was also noted. In comparison, her younger sister displayed the classic atrophic changes and white matter loss of AGS. The diagnosis of AGS was confirmed by sequence analysis, which identified a previously reported homozygous RNASEH2B mutation, c.554 T > G (p.V185G). Parents were heterozygous for the same mutation. Further molecular analysis excluded mutations in potentially related manifestations of COL4A1 gene. This is the first report of chilblains associated with heterozygous RNASEH2B mutation. Further, the brain imaging findings appear particularly interesting, which until now has not been reported in any AGS patient. We discuss the possible reasons for this unusual presentation.

Megalencephalic leukoencephalopathy with cysts in twelve Egyptian patients: novel mutations in MLC1 and HEPACAM and a founder effect

Two genes causing megalencephalic leukoencephalopathy with subcortical cysts (MLC) have been discovered so far. Here, we identified MLC1 and HEPACAM mutations in ten and two patients, respectively. The molecular results included an unreported inframe duplication mutation (c.929_930dupCTGCTG; p.L309dup) of MLC1 and a novel missense mutation c.293G>A (p.R98H) of HEPACAM. Further, the previously reported missense (c.278C>T; p.S93L) and the deletion/insertion (c.908_918delinsGCA; p.V303Gfs*96) were found in one and 8 patients (75 %), respectively. The 8 patients carrying the p.V303Gfs*96 shared a similar haplotype suggesting a founder effect. All mutations were in the homozygous state proving the autosomal recessive mode of inheritance. The core phenotype of macrocephaly, subcortical cysts and white matter appeared homogeneous although the patients differed in the onset, clinical course, disease severity and brain imaging findings. Our study expands the spectrum of mutations in MLC1 and HEPACAM and supports the genetic and clinical heterogeneity. Further, It confirms c.908_918delinsGCA (p.V303Gfs*96) as a founder mutation among Egyptian patients. This finding will contribute to provide targeted testing for this mutation in MLC patients in our population.

Assessment of interferon-related biomarkers in Aicardi-Goutières syndrome associated with mutations in TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, and ADAR: a case-control study

BACKGROUND

Aicardi-Goutières syndrome (AGS) is an inflammatory disorder caused by mutations in any of six genes (TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, and ADAR). The disease is severe and effective treatments are urgently needed. We investigated the status of interferon-related biomarkers in patients with AGS with a view to future use in diagnosis and clinical trials.

METHODS

In this case-control study, samples were collected prospectively from patients with mutation-proven AGS. The expression of six interferon-stimulated genes (ISGs) was measured by quantitative PCR, and the median fold change, when compared with the median of healthy controls, was used to create an interferon score for each patient. Scores higher than the mean of controls plus two SD (>2·466) were designated as positive. Additionally, we collated historical data for interferon activity, measured with a viral cytopathic assay, in CSF and serum from mutation-positive patients with AGS. We also undertook neutralisation assays of interferon activity in serum, and looked for the presence of autoantibodies against a panel of interferon proteins.

FINDINGS

74 (90%) of 82 patients had a positive interferon score (median 12·90, IQR 6·14-20·41) compared with two (7%) of 29 controls (median 0·93, IQR 0·57-1·30). Of the eight patients with a negative interferon score, seven had mutations in RNASEH2B (seven [27%] of all 26 patients with mutations in this gene). Repeat sampling in 16 patients was consistent for the presence or absence of an interferon signature on 39 of 41 occasions. Interferon activity (tested in 147 patients) was negatively correlated with age (CSF, r=-0·604; serum, r=-0·289), and was higher in CSF than in serum in 104 of 136 paired samples. Neutralisation assays suggested that measurable antiviral activity was related to interferon α production. We did not record significantly increased concentrations of autoantibodies to interferon subtypes in patients with AGS, or an association between the presence of autoantibodies and interferon score or serum interferon activity.

INTERPRETATION

AGS is consistently associated with an interferon signature, which is apparently sustained over time and can thus be used to differentiate patients with AGS from controls. If future studies show that interferon status is a reactive biomarker, the measurement of an interferon score might prove useful in the assessment of treatment efficacy in clinical trials.

FUNDING

European Union's Seventh Framework Programme; European Research Council.

Schistosoma hematobium soluble egg antigens induce proliferation of urothelial and endothelial cells

Bladder carcinoma accounts for 26% of reported human malignancies in Egypt, and has been strongly associated with urinary schistosomiasis. Nevertheless, the immediate role of schistosomal egg proteins in bladder carcinogenesis is unexplored. We investigated the effects of crude soluble egg antigens (SEA) of Schistosoma hematobium on urothelial cell proliferation. The proliferation of bovine endothelial Endo, human urothelial J82 and smooth muscle SMC cell lines was assessed by low-density growth assays. SEA induced proliferation of both J82 and Endo cells in a dose-dependent fashion, but not SMC. Preboiling or proteinase K treatment of SEA abolished its effect. In addition, SEA enhanced urothelial expression of B-cell translocation protein (BTG1) and human proliferating cell nuclear antigen (PCNA) mRNAs. Given the strong correlation between cell proliferation and carcinogenesis, the findings suggest that crude SEA may play some role in schistosomal bladder carcinogenesis.

Haplotypes and mutations of the PAH locus in Egyptian families with PKU

A high degree of molecular heterogeneneity at the phenylalanine hydroxylase (PAH) locus was established by examining RFLP haplotypes and PAH mutations in the families of 13 Egyptians with phenylketenouria (PKU). Thirteen different haplotypes were unequivocally determined in these kindreds. Haplotypes 1.8, 3.9, 4.3, 7.8, 22.11, 27.6, and 52.8 were found segregating with normal chromosomes, whilst haplotypes 1.8, 5.9, 23.8, 32.8, the newly assigned 73.9, and two as yet incomplete but novel haplotypes were found segregating with the mutant chromosomes. There was no particular preference for a single haplotype among normal or mutant chromosomes. Nine different mutations were also identified among the 26 alleles. IVS 10nt11g (8/26), IVS 2nt5g-c (4/26), R261Q (3/26), R176X (2/26), Y206D (2/26), S231P (2/26), Y198fs [593-614del22bp]; (2/26), G46fs [136/137delG]; (1/26), and E178G (1/26). Six of these mutations (IVS 2nt5g-c, R176X, Y198fs, R261Q, S231P, and IVS 10nt11g) are common to other Mediterranean populations. Two mutations not previously reported in the Mediterranean basin were also observed (Y206D and G46fs). These intriguing preliminary findings confirm IVS 10nt11g as a major mutation among Mediterranean mutations and demonstrate the need for a more comprehensive study of Arab populations to confirm the uniqueness of the two novel mutations to the Egyptian population.