Gilbert syndrome acts as a risk factor of developing gallstone among ß hemoglobinopathy Tunisian patients.

BACKGROUND: As a result of chronic hemolysis, hyperbilirubinemia is often observed, leading to the formation of pigment cholelithiasis which could be busted by the presence of uridine diphosphoglucuronosyltransferase 1A1 defects. AIM: Herein, we investigated the effect of glibert mutation on the occurrence of pigment cholelithiasis in Tunisian patients with beta (ß) hemoglobinopathy including sickle cell anemia and ß thalassemia (minor). SUBJECTS AND METHODS: Our study included 151 subjects divided in 75 SCA patients and 76 ß thalassemia patients. Both groups of patients were divided into two sub-groups according to the presence or absence of cholelithiasis. The relationship between A(TA)nTAA variation of UGT1A1 gene, the serum bilirubin level and the occurrence of cholilithiasis was investigated. RESULTS: Our results show a significant association between genotypes carrying variant (TA)7 and hyperbilirubinemia (p<0.05). Furthermore, we demonstrated a significant association between (TA)6/(TA)7 and (TA)7/(TA)7 genotypes with cholelithiasis among sickle cell anemia and thalassemia patients (p<0.05). CONCLUSION: Altogether, our data provide evidence that genotypes (TA)6/(TA)7 and (TA)7/(TA)7 and (TA)7 variant present a risk factor of developing gallstone among ß hemoglobinopathy Tunisian patients.

Association between rs267196 and rs267201 of BMP6 gene and osteonecrosis among sickle cell aneamia patients.

AIMS: The skeletal manifestations of sickle cell disease are the result of changes in bone and bone marrow caused by chronic tissue hypoxia that is exacerbated by episodic occlusion of the microcirculation by the abnormal sickle cells. Furthermore, the occurrence of osteonecrosis is under the control of some modifier gene. BMP6 (Bone morphogenetic protein) has been reported as associated with osteonecrosis in sickle cell anemia (SCA). Herein, we intend to study the impact of rs267196, rs267201, rs408505 and rs449853 of BMP6 gene in the occurrence of osteonecrosis among sickle cell patients in Tunisia. METHODS: Our study involved 100 SCA patients among whom 19 have osteonecrosis of the head of the femur. The latter polymorphisms of BMP6 gene were analyzed for all subjects by PCR/sequencing. To test for trait association with the candidate SNPs, genotype and allele frequencies between cases (osteonecrosis group) and controls (non-osteonecrosis group) were compared using Pearson's chi_square test with a significance threshold of P<0.05 (compare 2, version 1.02). RESULTS: Our findings showed that the patients carried genotype TA of rs 267196 and genotype AG of rs267201 present a high risk factor for developing osteonecrosis RR=1.317 and RR=1.3 respectively. The results showed a significant association between the alleles A of rs 267196 and G of rs267201 and osteonecrosis P=0.0023; RR=2.42 and P=0.041; RR=2.24 respectively. Interestingly, SCA patients with the combined genotype TA/AG were found to be at higher risk of developing osteonecrosis (P=0.009). As for rs408505 and rs449853 of BMP6 gene no significant association was found among SCA patients.

Early complication in sickle cell anemia children due to A(TA)nTAA polymorphism at the promoter of UGT1A1 gene.

AIM: To determine the implication of the polymorphism, namely, A(TA)nTAA of UGT1A1 in lithogenesis for the first time in Tunisia among sickle cell anemia (SCA) children patients. MATERIAL AND METHODS: Our study was performed in 2010 and it involved 76 subjects chosen as control group characterized with normal hemoglobin status and presence of cholelithiasis and 102 SCA pediatric patients among whom 52 have cholelithiasis. We analyzed the polymorphism A(TA)nTAA at the UGT1A1 promoter and the relationships between the various A(TA)nTAA genotypes and alleles and bilirubin levels and occurrence of cholelithiasis. RESULTS AND DISCUSSION: The repartition of genotypes found according to serum bilirubin level shows a significant association between genotypes carrying variant (TA)7 and hyperbilirubinemia (P < 0.05). We demonstrated the association of two genotypes with gallstones formation among SCA children patients: (TA)7/(TA)7 and (TA)7/(TA)8 with P = 8.1 × 10⁻8 and P = 0.01, respectively. (TA)7 and (TA)8 allele variants act as a risk factor for early gallstones formation in SCA patients with P = 5.8 × 10⁻9 and P = 0.01, respectively. As for the control group only the genotype (TA)7/(TA)7 presented a risk factor for gallstones formation. CONCLUSION: The novelty of this report is that it is the first time that a similar study was made on the Tunisian children sickle cell population and that the results show a clear association of (TA)7 variant in early gallstones formation in Tunisian SCA children. Interestingly our findings highlighted the association of (TA)8 variant as well, which was not found in previous studies.

Early complication in Sickle Cell Anemia children due to A(TA)_n TAA polymorphism at the promoter of UGT1A1 gene.

AIM: To determine the implication of the polymorphism namely A(TA)nTAA of UGT1A1 in lithogenesis for the first time in Tunisia among sickle cell anemia (SCA) children patients. MATERIAL AND METHODS: Our study was performed in 2010 and it involved 76 subjects chosen as control group characterized with normal hemoglobin status and presence of cholelithiasis and 102 SCA pediatric patients among whom 52 have cholelithiasis. We analyzed the polymorphism A(TA)_{n} TAA at the UGT1A1 promoter and the relationships between the various A(TA)_{n} TAA genotypes and alleles and bilirubin levels and occurrence of cholelithiasis. RESULTS AND DISCUSSION: The repartition of genotypes found according to serum bilirubin level shows a significant association between genotypes carried variant (TA)_{7} and hyperbilirubinemia (p< 0.05). We demonstrated the association of two genotypes with gallstones formation among SCA children patients: (TA)_{7}/(TA)_{7} and (TA)_{7}/(TA)_{8} with p=8.1 × 10^{ - 8} and p=0.01 respectively. (TA)_{7} and (TA)_{8} allele variants act as a risk factor for early gallstones formation in SCA patients with p=5.8 × 10^{ -9} and p=0.01 respectively. As for the control group only the genotype (TA)_{7}/(TA)_{7} presented a risk factor for gallstones formation. CONCLUSION: The novelty of this report is that it is the first time that a similar study was made on the Tunisian children sickle cell population and that the results show a clear association of (TA)_{7} variant in early gallstones formation in Tunisian SCA children. Interestingly our findings highlighted the association of (TA)_{8} variant as well, which was not found in previous studies.