Suad AlFadhli

Mutations in the RNA Granule Component TDRD7 Cause Cataract and Glaucoma

A Tudor domain protein mediates posttranscriptional control of gene expression and is required for eye-lens development. The precise transcriptional regulation of gene expression is essential for vertebrate development, but the role of posttranscriptional regulatory mechanisms is less clear. Cytoplasmic RNA granules (RGs) function in the posttranscriptional control of gene expression, but the extent of RG involvement in organogenesis is unknown. We describe two human cases of pediatric cataract with loss-of-function mutations in TDRD7 and demonstrate that Tdrd7 nullizygosity in mouse causes cataracts, as well as glaucoma and an arrest in spermatogenesis. TDRD7 is a Tudor domain RNA binding protein that is expressed in lens fiber cells in distinct TDRD7-RGs that interact with STAU1-ribonucleoproteins (RNPs). TDRD7 coimmunoprecipitates with specific lens messenger RNAs (mRNAs) and is required for the posttranscriptional control of mRNAs that are critical to normal lens development and to RG function. These findings demonstrate a role for RGs in vertebrate organogenesis.

Molecular characterization of glucose-6-phosphate dehydrogenase gene defect in the Kuwaiti population.

CONTEXT Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the most common human enzyme deficiencies. More than 130 different molecular abnormalities have been described worldwide, with considerable variation in the enzyme among various racial groups. Data from Kuwaiti populations are scarce, and the studies available are the result of screening male blood donors who may not be truly representative of the Kuwaiti population. OBJECTIVE The objective of this study was to investigate the mutation spectrum of the G6PD gene among Kuwaiti Arabs. DESIGN DNA was extracted from 82 G6PD-deficient Kuwaiti subjects (75 men and 7 women) and screened for gene mutations using polymerase chain reaction/restriction fragment length polymorphism and polymerase chain reaction/single-strand conformation polymorphism followed by direct sequencing. A total of 1209 randomly selected Kuwaiti adult subjects of both sexes were then screened for any characterized mutation. RESULTS G6PD Mediterranean(563C-->T), and A-(202G-->A,376A-->G) genotypes were characterized as the most common variants among the G6PD-deficient population, representing 0.742 and 0.124 allele frequencies, respectively. The 2 previously described mutations, G6PD Chatham(1003G-->A) and Aures(143T-->C), were found at lower frequencies (0.101 and 0.034, respectively). The allele frequencies for these 4 G6PD variants among the randomly selected Kuwaitis were 0.035, 0.0074, 0.0046, and 0.0023 for Mediterranean, A-, Chatham, and Aures, respectively. CONCLUSION This study has characterized the molecular heterogeneity of G6PD variants among ethnic Kuwaitis. The findings suggest that gene flow from the Indian subcontinent, sub-Saharan African, and other parts of the Mediterranean may have contributed to the observed G6PD mutations seen in the Kuwaiti population.

Effects of Cigarette Smoking on Hematological Parameters and von Willebrand Factor Functional Activity Levels in Asymptomatic Male and Female Arab Smokers

Objectives: This study aimed at determining the effects of cigarette smoking based on gender, on several hematological parameters and von Willebrand factor protein in the asymptomatic Arab population of Kuwait. Subjects and Methods: Ninety-two subjects participated in this study: 55 males (31 smokers and 24 nonsmokers) and 37 females (18 smokers and 19 nonsmokers). Complete blood count results were obtained using Beckman Coulter Hematology Analyzer. Von Willebrand factor functional activity was determined using an enzyme-linked immunoassay-based test in which anti-von Willebrand factor IgG monoclonal antibody was used that recognizes a functional epitope of the protein. The coagulation profile was obtained using ACL® 9000 coagulation analyzer. Results: Male smokers had significantly higher levels of white blood cell count (p = 0.03) and von Willebrand factor protein levels (p = 0.029), and a significantly shorter thrombin time (p = 0.019) than nonsmokers. Smoking did not appear to affect any of the parameters analyzed in females as no significant difference was found between smokers and nonsmokers (p > 0.05). Conclusion: Our results showed that smoking affected white blood cell count and von Willebrand factor levels in males and not in females, and as such could be potential markers for smoking-induced endothelial damage in asymptomatic Arab male smokers.

Comparison of Erythrocyte Sedimentation Rate Measurement by the Automated SEDIsystemTM and Conventional Westergren Method Using the Bland and Altman Statistical Method

Objectives: To compare the performance of SEDIsystemTM, a fully automated analyzer for the measurement of the erythrocyte sedimentation rate (ESR), with the manual Westergren method. Materials and Methods: Both methods were applied to 150 randomly selected subjects. The linear regression and Bland and Altman data analysis methods were used to measure the agreement between the automated and manual methods. Results: The regression analysis showed a good correlation between the two methods (r = 0.91). The Bland and Altman data analysis showed no systematic bias (95% confidence interval for mean difference); however, limits of agreement were between 11.52 and –37.88. This indicates that ESR values measured by the SEDIsystem may be 11.52 mm/h above or 37.88 mm/h below the reference method. A greater scatter of data was also observed with abnormally high (>25 mm/h) ESR results (mean of difference = –21.4 and limits of agreement = –45.2 and 2.26) compared with normal (<25 mm/h) readings (mean of difference = –3.9 and limits of agreement = –13.5 and 5.7). Conclusion: The Bland and Altman statistical analysis showed a wide degree of scatter between results obtained by the two ESR techniques that was not clearly demonstrated using the linear regression analysis. The automated system was found to underestimate ESR with the Bland and Altman statistical analysis, and therefore a correction factor is recommended.

Population genetics of 17 Y-STR markers in West Libya (Tripoli region).

Seventeen Y-chromosomal Short Tandem Repeats (Y-STR) included in the AmpFlSTR Y-filer PCR Amplification kit (Applied Biosystems) (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and GATA H4) were genotyped in a population sample of 176 unrelated males from western Libya (Tripoli region). A total of 142 different haplotypes were found, 124 being unique. Haplotype diversity was 0.9950. Both R(ST) pairwise analyses and multidimensional scaling plot show a close genetic relationship between Tripoli and North African populations.

Influence of Endothelial Nitric Oxide Synthase Gene Intron-4 27bp Repeat Polymorphism on Its Expression in Autoimmune Diseases

The purpose of this study was to analyse the effect of the T-786C polymorphism and intron 4 27 bp variable number tandem repeat(VNTR) eNOS markers for their potential association with Systemic Lupus Erythematosus(SLE), Hashimotos thyroiditis(HT) and Rheumatoid arthritis(RA) as well as to explore their effect on eNOS mRNA expression and nitrate production(NOx). Kuwaitis (n = 383) matched by age, gender and ethnicity were genotyped by fluorescent-labelled-restriction fragment length polymorphism (RFLP) and fragment analysis. Expression of eNOS mRNA was analysed using RT-PCR and sera from subjects were screened for NOx using ELISA. Analysis of the allelic frequency revealed a significant association of the 4b allele with susceptibility to SLE (p = 0.0092, OR = 1.76). The 4bb genotype was found to be associated with SLE (p = 0.0076, OR = 1.97) and HT (p = 0.05, OR = 1.81). Allelic and genotypic distribution did not differ between RA patients and healthy control subjects. The 4bb genotype resulted in reduced expression of eNOS mRNA in SLE, RA and HT, but only the reduction in HT was significant (p = 0.05). The 4ab genotype revealed a significant association with increased eNOS expression in HT (p = 0.03) and RA (p = 0.014) patients, and elevated NOx levels were detected in the autoimmune disease cohorts (p < 0.05) when compared to healthy control subjects. The T-786C SNP failed to show a significant association (p > 0.05) with SLE, HT, and RA patients. This study is the first to reveal a significant association between the 4bb genotype of the 27 bp VNTR and susceptibility to HT. The expression of eNOS is related to the number of 27 bp repeats, with heterozygous 4bb repeats showing a decrease in eNOS expression. eNOS – endothelial nitric oxide synthase.

Genetic structure of Kuwaiti population revealed by Y-STR diversity

In this study, a sample of 126 Kuwaiti was analysed using 12 Y-chromosome short tandem repeat (STR) polymorphisms. A total of 101 different haplotypes were identified, among which 87 were individual specific. The high haplotype diversity (0.994) supports the usefulness of Y-STR markers in Kuwaiti population diversity investigation. Our results suggest a close genetic relationship between Kuwait and other populations of the Arabian Peninsula, and an even more pronounced similarity of Kuwaiti populations and Yemenis and Saudi Arabians.

The Effect of UGT1A1 Promoter Polymorphism in the Development of Hyperbilirubinemia and Cholelithiasis in Hemoglobinopathy Patients

Present study was aimed to explore the effect of (TA)n UGT1A1 gene promoter polymorphism on bilirubin metabolism, bilirubinaemia, predisposition to cholelithiasis and subsequent cholecystectomy, in Sickle-Cell Anemia (SCA) and beta-Thalasemia major (bTH) in Kuwaiti subjects compared to other population. This polymorphism was analyzed and correlated to total bilirubin and cholelithiasis in 270 age, gender, ethnically matched subjects (92 bTH, 116 SCA and 62 Controls) using PCR, dHPLC, fragment analysis and direct sequencing. Four genotypes of UGT1A1 were detected in this study (TA6/6, TA6/7, TA6/8 and TA7/7). (TA)6/8 was found only in four individuals; hence it was not included in the analysis. There was a statistically significant association of genotypes with serum total bilirubin levels in both bTH and SCA groups (p<0.001). Subjects with (TA)7/7 had the highest total serum bilirubin level (178.7±3.5 µmole/l). A significant association was observed between allele (TA)7 and cholelithiasis development (p = 0.0001). The 40%, 67.5% and 100% of SCA with (TA)6/6, (TA)6/7 and (TA)7/7 respectively developed cholelithiasis and were subsequently cholecystectomized. Our results confirm UGT1A1 (TA)7 allele as one of the factors accounting for the hyperbilirubinemia and cholelithiasis observed in SCA and bTH.

Lack of Association of NOS3 and ACE Gene Polymorphisms with Coronary Artery Disease in Southern Tunisia

-arginine and molecular oxygen in vascular endothelial cells (Kincl et al.2009). Angiotensin-converting enzyme (ACE), present on the surface of vascularendothelial cells, generates the potent vasoconstrictor angiotensin II from angio-tensin I and inactivates the vasodilator bradykinin (Erdo¨s 1990). Angiotensin IImodulates NO synthesis in cardiovascular tissue, and NO modulates the action ofangiotensin II (Dubey et al. 1995; Nakagami et al. 1999). Many polymorphismslocated in the ACE and NOS3 genes have been reported to play a major role in thepathogenesis of coronary artery disease (CAD) and related outcomes (Cambienet al. 1992; Yoshimura et al. 2000; Bor-Kucukatay et al. 2010; Hamelin et al. 2011).The -T786C polymorphism in the NOS3 gene causes a reduction of promoteractivity and has been reported as a risk factor for coronary spasm in a Japanesepopulation (Nakayama et al. 1999). The Glu298Asp polymorphism has been

Investigation of the distribution of lymphocyte subsets and zinc levels in multitransfused β-thalassemia major patients.

Homozygous β‐thalassemia is a common genetic disorder in the Arabian Peninsula and an important cause of morbidity in Kuwait. The anemia is so severe that chronic blood transfusions, and the resulting iron overload, cause a shift in immunoregulatory balances and a deficiency in zinc. It was reported that individual immunological profile of CD8+ T‐lymphocytes may have a modifying effect on the severity of iron overload in HFE homozygous hemochromatosis patients, with low numbers being negatively correlated with the total amount of body iron stores. This has not been tested in thalassemia major patients. This study was designed to utilize flow cytometric immunophenotyping to characterize effects of regular blood transfusion, and high serum ferritin levels because of irregular use of iron chelation therapy on T lymphocytes (CD2, CD3, CD4 and CD8), B lymphocytes (CD19) and natural killer cells (CD56) and zinc levels in the blood of patients with thalassemia major (n = 49) and healthy normal controls (n = 60) in Kuwait. None of the patients had active infections. T‐cell markers’ percentage levels were comparable between patients and controls (P > 0.05), while B cell marker (CD19) was significantly higher in patients (P = 0.007). Patients had lower percentage levels of CD56 cells (P = 0.007) and normal serum zinc. All patients had high serum ferritin levels with no significant correlation to CD8+ T lymphocytes (P > 0.05). High iron stores did not have an effect on T lymphocytes’ profile, with normal zinc levels perhaps related to non compliance with chelation therapy. The high B cell marker may be indicative of stimulation of antibody producing cells as a result of regular blood transfusions.