The frequencies of one IL12B gene polymorphism (rs3212227) in Egyptians were the subject of a study by Youssef et al. (2013).  The study included 238 subjects: 100 healthy controls and 138 patients with HCV infection.  In healthy individuals, genotype frequencies for AA, AC, and CC were 46%, 39%, and 15%, respectively.  No significant difference was observed of the rs3212227 genotypes between controls and patients with HCV infection.  However, the C allele appeared as a predisposing factor for HCV infection in men, whereas it is a protective factor in women.

Picard et al. (2002) described ten patients from four different Saudi kindreds affected with IMD29.  All patients were born to first-cousin consanguineous parents, originating from and living in Saudi Arabia.  Cell lines derived from probands from three of these families were found to secrete neither of the IL12 protein chains.  WBCs from one of these patients were also found to not produce these proteins.  IL12B sequencing revealed the presence of a homozygous insertion mutation-g.315_316insA (315insA)- in all the affected Saudi children in the study.  This mutation was not found in 115 healthy Arabian control subjects.  The frameshift caused by this insertion was predicted to result in a premature termination at nt. 342-344.  The predicted mutant protein lacked all the residues shown by X-ray crystallography to be essential for the dimerization of IL12B with IL12A.  Since the four families were unrelated, the authors used polymorphic markers to genotype common haplotypes shared by the affected patients.  All the affected Saudi patients were found to share a 0.516 Mb common haplotype defined by three intragenic SNPs and two microstaellites, suggesting a founder event.  Using a mutation-dating method, the authors dated the closest common ancestor to 47 generation ago, providing an estimate of ~1,100 years for the founder mutation. 

Prando et al. (2013) extended this study by incorporating 14 Saudi consanguineous kindreds with IL12B deficiency.  These included the four families described by Picard et al. (2002) and an additional 10 kindreds with 17 affected children.  Patients in all families were found to be homozygous for the same insertion mutation (315insA) in the IL12B gene.  Using this larger group too, the date of the founder event was estimated at ~1,000 years ago.

Elloumi-Zghal et al. (2002) described three Tunisian patients with IL12B Deficiency from two different families.  Genotyping and sequencing indentified the same homozygous 8bp deletion in the IL12B gene.  This 297del8 mutation resulted in premature termination of the protein at nt. 342-344.  This mutation could not be detected in 30 control subjects.  Although the two families were unrelated, they originated from the same town in Central Tunisia, suggesting a common ancestor and a founder mutation. 

Prando et al. (2013) extended this study by incorporating six Tunisian kindreds with IL12B deficiency.  These included the two families described by Elloumi-Zghal et al. (2002) and an additional four kindreds with at least five affected children.  Patients in all families were found to be homozygous for the same insertion mutation in the 297del8 IL12B gene.  Later, Ben-Mustapha et al. (2014) studied this mutation in Tunisian patients and estimated that the founder mutation arose ~1,100 years ago.