Frequency of IL28B rs12979860 Single-Nucleotide Polymorphism Alleles in Newborn Infants and in Patients with Chronic Hepatitis C in Morocco

Abstract

Epidemiological and experimental evidence support the role of host genetics in treatment response and viral clearance in chronic hepatitis C (CHC). Recently, the CC genotype of IL28B single-nucleotide polymorphism (SNP) rs12979860 has been associated with spontaneous viral clearance and a better treatment response. The distribution of this polymorphism varies according to populations. Frequency of rs12979860 SNP alleles in the Moroccan population is unknown. The aim of our study was to estimate the frequency of the C allele of this SNP in the Moroccan population and, in parallel, in a cohort of Moroccan patients with CHC treated with pegylated interferon-alpha and ribavirin. We used real-time polymerase chain reaction assay based on TaqMan technology to determine the allele frequency of the rs12979860 SNP in 100 Moroccan newborn infants. We also compared the frequency of the CC genotype between two groups of patients with genotype 1-CHC treated by combination therapy: group1, n=30 patients, responders who achieved sustained viral response (SVR) and group2, n=30 patients, nonresponders. The rs12979860 C allele frequency was estimated to be 73% in the Moroccan population. The frequency of this allele in the group of patients with CHC was only 58.3%, and the CC genotype is more prevalent in group1 (62.5%) than in group 2. This is the first report providing genetic data related to the frequency of genetic polymorphisms of IL28B in Morocco. The C-allele frequency of the IL28B gene SNP rs12979860 in Morocco is higher than in the African populations. Distribution of this SNP distinguishes in a population of CHC between SVR and nonresponders. This result merits consideration and should be studied by analyzing a larger sample size of patients.