Qatar Foundation Annual Research Forum Volume 2011 Issue 1

Background: X-linked diseases are single gene disorders that are due to the presence of mutations in genes that reside on the X chromosome. X-linked recessive disorders are predicted from the family structure, where only boys are affected and there is no father to son transmission of the mutant allele. Heterozygous females are usually non-symptomatic carriers but can manifest a milder form of the disease. The identification of the genetic defect in X-linked disorders facilitates the diagnosis of affected individuals, aid in providing informative counseling and may help in prenatal diagnosis. Objectives: The study aims at mapping and identification of one gene responsible for congenital cataract and micropthalmia in a three-generation family.

Methods: We recruited 12 members of a family with a clear X-linked pattern of inheritance with three affected males, all showing congenital cataracts and microphthalmia. Gene mapping was attempted using a set of microsatellite markers selected to cover the whole X chromosome. Haplotypes were generated for all genotypes and the haplotypes were examined for alleles shared by the affected males and not shared by the unaffected males. Once the region of linkage was identified, we examined a few candidate genes by mutation analysis by resequencing in forward and reverse of one affected individual, one obligate carrier and one unrelated normal control. Candidate genes were chosen from the human genome public databases and were selected based on the possibility that they play a role in eye development or are expressed in fetal eyes.

Results: The region of linkage is a 50 Mb in the pericentromeric region of the X chromosome (Xp21.1-q21.2). The candidate genes ARR3, DACH2 and BCOR were resequenced in forward and reverse, but no variations were detected.

Conclusions: We were capable of mapping the gene responsible for congenital cataracts and microphthalmia to the pericentromeric region of the X chromosome. We examined 3 candidate genes but no variations were detected. Currently, we are examining other candidate genes. If no mutant alleles are identified by this candidate gene approach, we will proceed by performing whole exome sequencing of the X chromosome (after enrichment) utilizing the next generation sequencing technology.

Background: Autosomal recessive diseases are considered as a major group of single-gene disorders among Arab population. We have recruited a family with three siblings with a mental retardation (MR) syndrome who were born to consanguineous Qatari parents. The clinical problems comprised significant mental retardation, microsomia, signs of skeletal dysplasia, and thoracolumbar kyphosis. The oldest patient suffers also from epileptic seizures. Also, the parents and the other three of their six children are healthy. Causative genes and mapping strategy focused on large genomic regions demonstrating homozygosity in all of the affected individuals.

Objectives: Our goal is to identify the genetic causes of undelineated autosomal recessive disorders among Arab families.

Methods: Whole genome genotyping has been performed by (Illumina 300Kb SNPs). Followed by homozygosity mapping and linkage analysis. In addition, targeted resequencing of the candidate genes within the linked homozygous loci was performed.

Results and conclusions: Homozygosity mapping revealed a single large shared region of homozygous SNPs on the long arm of chromosome 4 flanked by rs28419770 (4q13.1) and rs4105671 (4q21.23). This block contains more than 120 genes, none of which has been implicated in MR or any of the above mentioned phenotype so far. Sequencing of candidate genes within the region revealed two novel missense variations in FRAS1 gene; an Arg3099Gln and Thr3149Met. Both variations were found in the three affected siblings in homozygous status, while the parents were heterozygous. Furthermore, these two variations have not been found in 140 individual controls in homozygous pattern, however, a heterozygous pattern of variations were found in three individuals only. Our future plan will be doing the whole exome sequencing for the shared region using next generation sequencing platform.

Prevalence rate of autism-spectrum disorders (ASD) in Qatar is uncertain, and speculation that their incidence is increasing continues to cause concern. Although the apparent increased prevalence of autism may reflect improved detection and recognition of autism and its variants. No comprehensive survey has been done to estimate the prevalence of autism in Qatar.

The target population for this study is children aged 3 through 18 years whose parents resided in Qatar.

Children with ASD in Qatar going to be identified using a two-phase process.

In Phase 1, children from a representative sample of all primary schools in Qatar going to be preliminarily screened using Social Communications Questionnaires, and those who are suspected to have ASD will be approached through phase 2. Review of records of children with possible ASD from the following institutions:

1). Shafallah Center for children with special needs records, which includes all children with preliminary diagnosis of ASD, who attends special classes for autism.

2). Other centers and school which has similar facilities.

3). Records from the Supreme Council of Health, Hamad Medical Corporation, and any other health centers.

In Phase 2, clinical evaluation is conducted by a developmental psychologist, and/or paediatrician. It includes a medical, developmental, and behavioural history; a standard physical and neurologic examination, In addition, the Autism Diagnostic Interview (ADI-R), and Autism Diagnostic Observation Schedule-G (ADOS-G) will be administered.

Preliminary analysis of 179 subjects showed the highest prevalence among age group 7–14 years (61%).

Male/female ratio was 82% /18%, which is around 5/1. Further works needed to calculate the total prevalence rate. Obtaining a reliable estimate is important in planning for providing the best health care and educational services needed to improve the overall outcome of autism.

Background: The number of genes identified to be responsible for autosomal dominant genetic conditions far exceeds those identified for autosomal recessive conditions. This is expected because autosomal recessive disorders are rare and a single large family or a large number of smaller families are needed for gene mapping and identification. However, this hurdle can be overcome by homozygosity mapping utilizing inbred families.

Objectives: The aim of this study is to map loci and identify genes that play a role in autosomal recessive disorders among Arab families and to examine their role with the final aim of outlining novel genes and pathways. The investigation capitalizes on utilizing large inbred families, as well as smaller inbred families, by employing homozygosity approaches for mapping the etiologic genes.

Methods: It includes the recruitment of families and obtaining detailed clinical, genealogical and genotypic data. Families with pedigrees that provide suggestive evidence of autosomal recessive mode of inheritance and with consanguinity are selected. Homozygosity mapping is done by genome wide SNP genotyping using dense chips, followed by linkage analysis.

Results: We performed homozygosity mapping on one recruited family to seek a region of homozygosity shared by affected individuals. This family includes eight individuals from 4 related sibships in an extended Palestinian family who suffer from congenital cataract. Homozygosity mapping revealed a region flanked by rs4276160 (3p22.1) and rs749512 (3p21.31) on the short arm of chromosme 3. This interval contains 92 genes, none of which has been implicated in eye disease. Further investigation for this family is currently underway using whole exome sequencing to identify the causative gene mutation. Other examples will be presented.

Conclusion: Homozygosity mapping utilizing inbred families is a very powerful tool for gene mapping in autosomal recessive families. However, the region of linkage is usually big and contains a large number of genes, which is prohibitive with the classic technology. Genomic approaches such as whole exome sequencing is yet another powerful tool to overcome this hurdle.

In Qatar, cardiovascular diseases are the leading cause of mortality and morbidity.

Cardiovascular diseases can be prevented and controlled by modifying lifestyle risk behaviours such as physical inactivity, unhealthy diet and smoking. Obesity as the result of physical inactivity and unhealthy diet raises the risk of heart diseases. Studies show that 62.6% of Qatari women were overweight and the prevalence of overweight is high among adult females with 80% of women 30 years and over. Qatar World Health Survey in 2006 shows that only 40% of Qatari women participated regularly in sports or other physical activities. Furthermore, waterpipe smoking is increasing across the Eastern Mediterranean.

Funded by the Qatar National Research Fund, the ultimate goal of this study was to find ways to effectively promote cardiovascular/coronary artery disease prevention and management activities among Qatari women (citizen and resident Arabic women) by exploring factors affecting the ways in which Qatari women participate in physical activities, healthy diet and smoking.

An exploratory qualitative research approach was used in this study, with a semi-structured questionnaire using open ended questions to gather data. Individual in-depth interviews were conducted with 50 Arabic women who are 30 years and over, have confirmed diagnosis of CVD/coronary artery diseases to investigate factors influence lifestyle risk behaviours associated with cardiovascular diseases amongst Qatari women (citizen and resident Arabic women).

The study's results show that social support networks; cultural beliefs, values, practices, and religion; rapid economic growth; changing environmental and social conditions influence women's participation on physical activities, dietary practices and smoking. Conclusion: Prevention of cardiovascular diseases and promotion of healthy lifestyle should consider women's specific health condition and socio-economic status; empower women to take charge of their health; facilitate women's informal and formal social support networks; provide culturally appropriate public education; create healthy environment with more recreational facilities for women and children.

Background: Genetic and environmental factors are highly related with gestational diabetes mellitus (GDM) and type 2 diabetes (T2D). Our objective was to explore whether some genetic variants such as rs12255372, rs7903146 of TCF7L2 gene are significantly associated with the risk of gestational diabetes mellitus among Arabian population.

Methods: A case control study was designed for such genetic association study. A total of 159 unrelated pregnant women (114 Arab; 40 gestational diabetes mellitus cases and 74 controls and 45 non-Arab; 11 gestational diabetes mellitus and 34 controls) were recruited from antenatal care unit of HMC. Blood sample were drawn for DNA extraction, then genotyped for TCF7L2 gene variants (rs12255372, and rs7903146) using TaqMan real time PCR assay. Plasma was used for biochemical analysis including glucose, insulin and adiponectin.

Results: The CC, CT and TT genotype frequencies of the TCF7L2 rs7903146 variants was not significantly different between the control and gestational diabetes mellitus cases (39.4%, 50,0%, 10.6% vs. 40.6%, 43.8%, and 15.6%, p=0.444) among Arab populations, respectively. Only, the T allele of rs12255372 variant was significantly associated with risk of gestational diabetes mellitus with odds ratio of 2.370, (95% of CI 1.010–5.563) with the p value of 0.047 among Arab subjects using the genetic dominant model after adjustment of BMI and age. The other polymorphism rs7903146 was not significantly associated with GDM among Arab and non-Arab subjects. No significant difference was observed for glucose, insulin and adiponectin hormone after 50g glucose load by genotyping of both variants.

Conclusion: The TCF7L2 rs12255372 variant is associated with an increased risk of gestational diabetes mellitus in Arab women. Further studies are needed with larger sample sizes.

Background: Caring for a child diagnosed with autism is strongly linked to maternal caregiving burden. It forces family members to modify their daily lives to suit their different reality and it imposes social, psychological, and economical hardships. No previous research has assessed the burden associated with caring for a child with autism on the lives of caregivers in Qatar or the Gulf country region.

Objective: To assess the burden of autism on the lives of caregivers of children with autism in Qatar.

Methods: Two groups of caregivers of children between 3 to 17 years old were recruited. The caregivers of children with autism (Autistic Group, or AG) were recruited from two developmental pediatric and children rehabilitation clinics in Qatar. The caregivers of typically-growing children (Non-Autistic Group, or NAG) were recruited during their visit for a family clinic of a primary health care facility for routine medical check-up. Data collected from both groups included demographic information of caregivers and children and several questions aimed at assessing the burden of caring for a child with autism. Items in questions were developed after a thorough literature review.

Results: Children in the AG spent more time indoors, watching television, or sleeping than children in the NAG (p=0.05). Around 50% of the caregivers in AG did not wish to answer questions about whether they would encourage their children to get married or become parents when they grow up. Half of the sample in the AG utilizes special education classes and other facilities, and the remaining half has access problems. Religious faith helps the majority of caregivers in coping with the burden associated with caring for a child with autism.

Conclusions: This study provided evidence for the impact of caring for a child with autism on the life of the caregivers. It also gave an insight into areas relating to support provided to children with autism and their caregivers and the status of the children with autism in different aspects. The findings should help health policy-makers provide better and more focused supports to the children with autism and their families.

Background: Pineal hormone melatonin (MEL) is a versatile molecule with diverse physiological roles ranging from circadian entrainment to anti-cancer effects. Clinical trials indicated that a co-application of cisplatin and melatonin improved the 1-year survival rate. Also, Futugami (2001) claimed melatonin enhances the sensitivity of an ovarian cancer cell line to cisplatin.

Objective: Here we study the anti-cancer effects of a co-application of cisplatin (CDDP, 1pM -10 mM - log10 scale) and melatonin (1pM – 100μM) on MCF-7 cells.

Methods: Cell viability was assessed through MTT assays and trypan blue exclusion tests.

Results: 1) a) CDDP causes concentration-dependent growth inhibition of MCF-7 cells at high concentrations (1–100 μM) over 24 and 48 hrs with an IC50 of 99.6 ± 5μM (24 hrs) b) Over a period of 6 days, 1uM CDDP causes significant (52.35 ± 0.64% of control) growth inhibition 2) MEL does not significantly inhibit MCF-7 cell growth over 24 hr and 6 day time points. 3) Simultaneous co-application of MEL with CDDP significantly (p ← 0.05) reverses 80?M CDDP induced growth inhibition over 24 hrs at physiological concentrations (0.1 – 10nM) (increase in growth by 21.4 ±} 1.8 %). 4) However, simultaneous co-application of MEL and CDDP does not significantly reverse the growth inhibition induced by 1μM CDDP over 6 days.

Conclusion: As reported by several labs, CDDP shows significant growth inhibition within 24 hrs only at high concentrations while long term growth inhibition is observed at low concentrations (1–10μM). The results indicate that the sub clone of MCF-7 cells used by us is melatonin “insensitive” as MEL does not have an anti-proliferative effect over the points tested. However, these cells are not completely irresponsive to MEL as MEL reverses CDDP induced growth inhibition at physiological concentrations. The question arises as to why such a “protection” is observed only at physiological concentrations. Moreover, this effect is only observed when acute cell death is induced at high concentrations and not at chronic low concentrations. To conclude, the results open up the interesting questions of the molecular basis of the protective effects of melatonin on CDDP induced cell death and melatonin “insensitivity”.

This study was carried out to examine the difference between the respiratory volumes in athlete and non-athlete adolescent females, how does exercise affect the respiratory volumes and how could the effects of exercise on the respiratory system affect the heart rate? Introduction: The respiratory and circulatory systems are the most important systems in the body as they involve vital organs (lungs and heart). They are affected by several factors, which may improve or weaken their function. Exercise positively affects their function. Methods: In this study 2 groups were compared: athletic and non-athletic females using a spirometer to measure the respiratory volumes before and after running. The heart rate and blood pressure were also measured in both groups. The statistical analysis and graphs were done using excel 2007. Results: The pre-test mean vital capacity in non-athletes was 2600.0± 496.7 and in athletes: 2642.9 ± 340.9. Whereas post-test mean vital capacity of lungs in non-athletes was 2385.7 ±429.8 and in athletes: 2428.6 ±407.1. Pre-test mean blood pressure in non-Athletes was 94.6 ± 9.3mmHg and in athletes was 86 ± 8.1 mmHg but post-test mean blood pressure in non-athletes was 113.8 ± 31.6 mmHg and in athletes: 99.1 ± 8.8 mmHg. The pretest mean heart rate in non-athletes was 89±5.2 beat per min while in the athletes it was 86 ± 6.5 beat per min. Conclusion: On the short term exercise increases the heart rate, decreases the blood pressure, decreases the lung capacity and increases tidal volume. Whereas long term effects involve increased lung capacity and tidal volume; and decreased blood pressure and heart rate.

The coagulation/fibrinolytic system controls the intravascular fibrin homeostasis; in addition to participating in a wide variety of physio-pathological processes. The components of the system have an influence on tumor metastasis, growth and invasion. This is a result of their involvement in tumor matrix construction, angiogenesis and cell migration.

Thrombosis of unexplained etiology among healthy and cancer patients; is a major cause of death. Several homeostatic markers are currently used to predict the advent of thrombosis. However, none of these markers directly indicate the course and progression of the disease; thus thrombosis remains unexplained.

Endothelial Protein C Receptor EPCR gene carries 13 single nucleotide polymorphisms, which define 3 haplotypes: A1, A2 and A3. One of these, A3, encodes a protein, which is more sensitive than the other two in shedding enzymes. High levels of protein C are determined by PROCR haplotype 3. A3 haplotype reflects a high soluble Endothelial Protein C Receptor (sEPCR) level. Therfore, it is a candidate risk factor for venous thrombosis. We observed that the plasma concentration of sEPCR in cancer patients was much higher than that observed in controls. We suggest that sEPCR released from malignant cells could serve as a “trap” for protein C, preventing it's binding to EPCR on the surface of endothelial cells and induced thrombotic state.

We developed a method, based on activated Partial Thromboplastin Time, in order to analyze the ability of (EPCR) on the cancer cell membrane to trap circulating Activated Protein C (APC). This test is in conjunction with other specific tests used for assessing thrombotic state, such as the one to quantitate soluble fibrin and d-dimer.

Previous study of lung cancer patients, done by Department of Pathology, Free University Medical Center 2002, revealed a marked association between high EPCR levels; and poor survival or relapse in patients with stage I lung adenocarcinoma. The aim of our study is to investigate the role of sEPCR as a cause of thrombotic disorder, among cancer patients. Furthermore, to detect whether EPCR of cancer cells is haplotype 3, that affect on the level of sEPCR.