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Celiac disease (CD), a multi-factorial auto-inflammatory disease of the small intestine, is known to occur in both sporadic and familial forms. Together HLA and Non-HLA genes can explain up to 50% of CD’s heritability. In order to discover the missing heritability due to rare variants, we have exome sequenced a consanguineous Saudi family presenting CD in an autosomal recessive (AR) pattern. We have identified a rare homozygous insertion c.1683_1684insATT, in the conserved coding region of AK5 gene that showed classical AR model segregation in this family. Sequence validation of 200 chromosomes each of sporadic CD cases and controls, revealed that this extremely rare (EXac MAF 0.000008) mutation is highly penetrant among general Saudi populations (MAF is 0.62). Genotype and allelic distribution analysis have indicated that this AK5 (c.1683_1684insATT) mutation is negatively selected among patient groups and positively selected in the control group, in whom it may modify the risk against CD development [p<0.002]. Our observation gains additional support from computational analysis which predicted that Iso561 insertion shifts the existing H-bonds between 400th and 556th amino acid residues lying near the functional domain of adenylate kinase. This shuffling of amino acids and their H-bond interactions is likely to disturb the secondary structure orientation of the polypeptide and induces the gain-of-function in nucleoside phosphate kinase activity of AK5, which may eventually down-regulates the reactivity potential of CD4+ T-cells against gluten antigens. Our study underlines the need to have population-specific genome databases to avoid false leads and to identify true candidate causal genes for the familial form of celiac disease. [ABSTRACT FROM AUTHOR]

Aim Uterine leiomyomas (UL) are smooth muscular nodes, whose growth is dependant up on the complex interplay of hormones with genes and uterine physiology. Global statistics indicate the role of ethnic and racial background as contributory factors for UL development. Owing to the lack of data, this study aimed to examine the association between genetic polymorphisms and susceptibility of Arab women of developing UL. Methods We genotyped 105 UL patients and 112 healthy controls for five genetic polymorphisms through real time PCR method. The strength of the association between genotype and allele frequencies with risk of developing UL was tested with their χ2 and odds ratio (OR) values. The synergistic cooperation between genetic polymorphisms was estimated through multifactor dimensionality reduction assay. Results We found that Saudi women with the AG genotype for the rs12484776 polymorphism are at a 2.6-fold higher risk of developing UL compared to those with other genotypes (OR, 2.69; 95% confidence interval [CI]: 1.45-5.00; P < 0.001). This significance persisted even under co-dominant models (i.e., AA vs GG + AG [OR, 2.74; 95%CI: 1.48-5.08; P = 0.001; and AG vs GG + AG [OR, 2.41; 95% CI: 1.33-4.39; P = 0.003). Genotype distribution frequencies for rs1056836, rs7913069, rs2280543, and rs4247357 were not shown to elevate the disease risk (for all tests P > 0.05). Conclusion The rs12484776 significantly contributes to UL risk among Saudi women, both in single and also in synergistic cooperation with rs2280543, rs7913069, and rs1056836 markers. Our results have yielded mixed findings in replicating European- and Japanese-specific UL genetic susceptibility loci among a geographically and culturally distinct population of the Saudi Arabian Peninsula. [ABSTRACT FROM AUTHOR]

Coronary artery disease (CAD) is a multifactorial disease with the underlying involvement of environment, life style and nuclear genetics. However, the role of extranuclear genetic material in terms of somatically acquired mutations in mitochondrial tRNA and protein coding genes in the initiation or progression of CAD is not well defined. Hence, in the present study, right atrial appendage tissues and matched blood samples of 150 CAD patients were screened for mutations in nucleotide regions encompassing the Cytochrome c oxidase subunit II (MT-CO2), tRNA lysine (MT-TK), ATP synthase F0 subunit 8 (MT-ATP8) and Cytochrome b (MT-CYB) genes of mitochondrial DNA. We have found 9 different somatic mutations in 6 % of the CAD patients. Out of these mutations, 4 each were localized in MT-TK gene (T8324A, A8326G, A8331G and A8344G) and MT-CYB genes (T15062C, C15238A, T15378G and C15491G) in addition to one mutation in non-coding region 7 (A8270T) of mitochondrial genome. In addition, we noticed that majority (85.3 %) of CAD patients showed double repeats of germ-line 'CCCCCTCTA' intergenic sequence between MT-CO2 and MT-TK genes. Our in-silico investigations of missense mutations revealed that they may alter the free energy and stability of polypeptide chains of MT-CYB protein of complex III of mitochondrial respiratory chain. Based on our study findings, we hypothesize that the somatically acquired variations in MT-TK and MT-CYB genes may negatively impact the energy metabolism of cardiomyocytes in right atrial appendage tissues and contribute in the cardiac dysfunction among CAD patients. In conclusion, our findings may be likely to have potential implications in understanding the disease pathophysiology, diagnosis as well as for the better therapeutic management of CAD patients. [ABSTRACT FROM AUTHOR]