Abstract
Background: Asthma is a “complex” heritable disorder, candidate genes that may be involved in the pathogenesis of asthma including: interleukin 4 (IL-4), IL-5, IL-9, and IL-13 (Postma et al. 1995). Asthma prevalence in Sudan was found to be 12.5% in children aged 13-14 year in the Capital Khartoum (Mohamed et al. 1999).
Objectives: To detect polymorphisms of IL-9 in chromosome 5 and iIL-4R in chromosome16 contributing to asthma and to estimate the environmental components: Total immunoglobulin E levels, skin prick test, and eosinophil count in Sudanese population.
Methods: Seventy, nuclear and extended families were sampled in the initial phase of the study. Ventilatory function, skin, prick test blood sample for DNA analysis, immunoglobulin E, eosinophil count were carried out in the whole sample. Genotyping for IL-9, IL-4R and IL-13, polymorphisms using PCR were also carried out for a subset of the sample.
Results: Phenotypic analyses of the pedigrees suggest a likely genetic cause for asthma, as shown in one extended family. Level of total immunoglobulin E was found to be 71% in asthmatic, and 24% in non asthmatic. Eosinophil count was found to be 58% in asthmatic, while found to be 17.4% in non asthmatic. Hypersensitivity symptoms to six allergens showed positive skin test. (p = 0.00). Genotyping for IL-9, IL-4R suggest the presence of association for bothIL-9 and IL4R (P=0.008&0.007).
Conclusions: Asthma runs in families showing strong linkage to genes. There seems to be sufficient phenotypic and genotypic indicators to suggest a genetic predisposition component to asthma among Sudanese, and warrant some furthers investigation.
- © 2011 ERS