Genetic analysis of the SNPforID 34-plex ancestry informative SNP panel in Tunisian and Libyan populations.

A total of 149 unrelated and healthy individuals comprising: Tunisian Berbers, Tunisians with Andalusian origin and Libyans were typed with the SNPforID 34-plex ancestry informative marker (AIM) SNP panel. Results of 31 of the 34 SNPs are presented and no deviations from Hardy-Weinberg equilibrium were observed after Bonferroni correction (p=0.00161) except rs722098 (p=0.0000). Comparisons of allele frequencies showed high divergence values between North Africans and Europeans (δ>30%) in markers: rs4540055 (allele A) and rs16891982. Our study adds data that can be used as training set genotypes for future ancestry investigations in forensic cases and suggests these AIM-SNPs can successfully differentiate North Africans and Mediterranean Europeans.

Interleukin 10 promoter region polymorphisms in inflammatory bowel disease in Tunisian population.

OBJECTIVE: To test whether IL-10 promoter region polymorphisms are associated with susceptibility to inflammatory bowel disease, we examined the contribution of interleukin- 10 (IL-10) gene polymorphisms to Crohn's disease (CD) and Ulcerative colitis disease (UC) occurrence and also to CD phenotype. MATERIELS AND METHODS: SNPs at positions -627 (C > A) and -1117 (G > A) in the IL-10 promoter were determined in a sample of 105 Tunisian patients with IBD (75 CD and 30 UC) and 90 matched healthy controls. RESULTS: The 627 CA genotype is associated with ileal location (p = 0.015) and with stricturing (p = 510-3) and penetrating (p = 310-3) presentation of CD. An additive effect between IL10 variants and CARD15 3020 insC mutation (p = 0,006) on severe forms of CD was shown. CONCLUSIONS: In Tunisian population, the 3020insC insertion in NOD2/CARD15 gene is a marker of susceptibility to CD, while the A allele at position -627 in the IL-10 promoter increases the risk of CD ileal location and severe disease presentation. A genetic epistasis between IL-10 gene polymorphisms and CARD15/NOD2 gene mutation was suggested.

3020insC insertion in NOD2/CARD15 gene, a prevalent variant associated with anti-Saccharomyces cerevisiae antibodies and ileal location of Crohn's disease in Tunisian population.

OBJECTIVE: Our aim is to investigate the relation between CARD15 3020insC mutation, anti-Saccharomyces cerevisiae antibodies (ASCA) and disease phenotype, in Tunisian inflammatory bowel disease (IBD) patients. MATERIALS: A hundred Tunisian patients with IBD (75 Crohn's disease CD and 25 ulcerative colitis UC) and 60 matched healthy controls were studied. METHODS: CARD15 mutation was analysed by using an allele-specific polymerase chain reaction and sequencing. Assessment of ASCA in serum was performed by ELISA. RESULTS: The frequency of the mutation was significantly higher in Crohn's disease than in control (p = 0,0005; OR = 20.45; CI 95% = 2.86-413.85) and did not differ statistically in UC group (p = 0, 05) from control. ASCAs were present in 60% of CD and 20, 8% of UC. CONCLUSION: This study suggests that in northern Tunisian population, 3020insC mutation in NOD2/CARD15 gene is a prevalent mutation leading to the typical Crohn's disease including ileal location, stricturing and penetrating clinical types and ASCA expression.

Complete mutation screening and haplotype characterization of BRCA1 gene in Tunisian patients with familial breast cancer.

Breast cancer, the most commonly diagnosed cancer in women, is the second leading cause of cancer death in women worldwide. To investigate the contribution of BRCA1 gene mutations to familial breast cancer in Tunisia, 32 unrelated patients who had at least one first degree relative affected with breast and/or ovarian cancer were analysed. BRCA1 mutation analysis was performed by DNA sequencing of all BRCA1 exons. We identified four different BRCA1 frameshift mutations: c.4041delAG, c.2551delG and c.5266dupC already been described and one novel mutation, c.211dupA, observed in two unrelated families. C.5266dupC has previously been found among Jewish Ashkenazi and Eastern European populations. Our study describes it in Arabic/Berber population. Five out of thirty two familial cases had deleterious BRCA1 mutations. Fifteen additional cases carried unclassified variants (UV) or single nucleotide polymorphisms (SNPs). Our study is the first molecular investigation on the role of BRCA1 in hereditary breast cancer in North Tunisia.

Data for 15 autosomal STR markers (Powerplex 16 System) from two Tunisian populations: Kesra (Berber) and Zriba (Arab).

Allele frequencies, together with some parameters of forensic interest, for 15 STRs included in the Powerplex 16 System (CSF1PO, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, FGA, Penta D, Penta E, TH01, TPO and VWA) were estimated from two samples of unrelated individuals from Tunisia, of different ethnicity: Kesra (Berber) and Zriba (Arab). No deviations from Hardy-Weinberg equilibrium were observed after Bonferroni's correction for the number of loci analysed. Comparative analyses between our population data and other North African databases showed that significant differences were concentrated on loci with lowest values of diversity (mainly CSF1PO and D13S317), irrespective of ethnicity and geographic location.

Y chromosome microsatellite variation in three populations of Jerba Island (Tunisia).

Six Y-chromosome linked microsatellites were typed in a sample of 135 unrelated males representing three different ethnic groups: Arabs, Berbers and Blacks of Jerba Island (Tunisia). Analysis of variation at the six Y chromosome STRs showed significant differences in allele distributions between the Black group and the two other Islander groups. The Black group revealed the highest level of genetic diversity as compared to Arabs and Berbers, while the latter group was the most homogeneous. Allele frequencies obtained for the three islander groups analysed were compared to data available for some European, Mediterranean and African populations. Principal-coordinate analyses showed genetic differentiation between the three geographically closed groups of Jerba. The absence of the YAP insertion marker and the position of Arabs and Jerban Blacks near the European cluster would suggest their relative 'admixture' with European populations.

Contribution of blotting techniques to the study of rapeseeds (Brassica napus L.) lipases.

A recent advance in the study of plant lipases involving immunological techniques is presented. In an attempt to characterize lipases of cotyledons from germinating rapeseed seedlings and to investigate an eventual cross-reactivity with animal lipases, we have prepared anti-porcine pancreatic lipase antibodies raised in rabbit. It is shown by enzyme-linked immunosorbent assay and dot-blotting that these antibodies react with lipases in the rapeseed crude extract and in the different cellular fractions obtained by differential centrifugation. Preincubation of the antiserum with the rapeseed crude extract affects the amount of antibodies binding to the porcine pancreatic lipase. We demonstrate immunochemical cross-reactivity between rapeseed and porcine pancreatic lipase. Using the immunoblotting procedure, it is found that antibodies bind specifically to a single polypeptide with a molecular mass of about 55 kDa. Rapeseed lipase activity decreased after immunoprecipitation suggesting that antibodies were bound to some catalytic site residues. We conclude from the data obtained in this study that the two different lipase species present close similarities in amino acid sequence and antigen characteristics.