Haplotype reconstruction was performed as previously described [23] . Haplotype-tagged single nucleotide polymorphisms (htSNPs) were determined using the HaploBlockFinder software with a minor allele frequency over 5% [24] and numbers were redefined compared to our previous publication [23] for their frequency in the present study population. Ten htSNPs were selected corresponding to the 10 major haplotypes from the 20 SNPs (rs number in Table S1 ) found in the Zimbabwean population as we previously described [23] . These htSNPs along with the 3 others exon 4 mutations were genotyped in the 197 infants by direct PCR sequencing analysis as previously described [23] . Putative transcription factors binding sites in promoter region were analysed with TESS interface (http//:www.cbil. upenn.edu/tess) using the TRANSFAC database.