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Abstract Presenting processed antigens to CD4+ lymphocytes during the immune response involves major histocompatibility complex class II molecules. MHC class II genes transcription is regulated by four transcription factors: CIITA, RFXANK, RFX5 and RFXAP. Defects in these factors result in major histocompatibility complex class II expression deficiency, a primary combined immunodeficiency frequent in North Africa. Autosomal recessive mutations in the RFXANK gene have been reported as being the principal defect found in North African patients with this disorder. In this paper, we describe clinical, immunological and genetic features of 11 unrelated Algerian patients whose monocytes display a total absence of MHC class II molecules. They shared mainly the same clinical picture which included protracted diarrhoea and respiratory tract recurrent infections. Genetic analysis revealed that 9 of the 11 patients had the same RFXANK founder mutation, a 26 bp deletion (named I5E6-25_I5E6+1, also known as 752delG26). Immunological and genetic findings in our series may facilitate genetic counselling implementation for Algerian consanguineous families. Further studies need to be conducted to determine 752delG26 heterozygous mutation frequency in Algerian population.

Objectives: To assess factors associated with prehypertension and hypertension among children in North Africa., Methods: An epidemiological observational, school- and college-based study among 3562 healthy children and adolescents to assess factors associated with blood pressure categories (normal, prehypertensive, hypertensive), including perinatal (gestational age, birth weight, breastfeeding) and current lifestyle characteristics (body mass index, time spent watching a screen and time spent exercising)., Results: Prevalence of hypertension increased with age from 8.7% between 6-10 years to 14.7% between 11-15 years, and 15.6% above 15 years. Prevalence of prehypertension and hypertension increased with body mass index from 9.9% and 11.5% among children not overweight to 15.6% (RR 1.58, 95% CI 1.24-2.02, P<0.001) and 17.2% (RR 1.50, 95% CI 1.22-1.85, P<0.001) among those overweight and to 26.8% (RR 2.72, 95% CI 2.04-3.64, P<0.01) and 32.3% (RR 2.82, 95% CI 2.27-3.50, P<0.01) among obese children. There was a trend of association of prehypertension with the time spent watching Television, internet and electronic games. Children whose mother or father had a history of hypertension had a trend to be prehypertensive or hypertensive. A parental hypertension was found in 33.6% of normotensive, 38.2% of prehypertensive, and 42.6% of hypertensive children (P=0.05). Children with prehypertension or hypertension were more likely to have a diabetic father or mother (22.8% and 22.6% vs 15.8%, respectively, P=0.01). Also, prehypertension and hypertension were associated with shorter gestational age, early birth, reduced birth weight, and shorter breastfeeding., Conclusion: Prehypertension and hypertension have a high prevalence among children in North Africa. They are associated with overweight, obesity, diabetes, a shorter gestational age, a lower birth weight and a shorter breastfeeding., Competing Interests: None., (AJCD Copyright © 2021.)