Amein K. Al-Ali

Vitamin D levels in healthy men in eastern Saudi Arabia.

Background: Studies in 1980s and 1990s indicated that vitamin D levels in the ethnic Saudi Arabian population were low but no studies since that time have evaluated vitamin D levels among healthy young or middle-aged Saudi men. Thus, we assessed the serum level of 25-hydroxyvitamin D (25OHD) among healthy Saudi Arabian men living in the Eastern Province. Subjects and Methods : One hundred males aged 25-35 years (the age range of peak bone mass) and 100 males aged 50 years or older were randomly selected and evaluated clinically, including measurement of serum calcium, parathyroid hormone (PTH) and serum 25OHD levels. Vitamin D deficiency was defined as a serum level of 25OHD of ≤20 ng/mL and insufficiency as a serum level between >20 ng/mL and < 30 ng/mL and normal ≥30 ng/mL. Results: The mean (SD) age of subjects in the younger age group was 28.2 (4.5) years. Twenty-eight (28%) had low 25OHD levels; 10 (10%) subjects were vitamin D deficient with a mean level of 16.6 (3.4) ng/mL and 18 (18%) were vitamin D insufficient with a mean level of 25.4 (2.7) ng/mL. In the older age group, the mean age was 59.4 (15.6) years and 37 (37%) had low 25OHD; 12 (12%) subjects were deficient with a mean 25OHD level of 16.7 (3.4) ng/mL and 25 (25%) were insufficient with a mean 25OHD level of 25.3 (3.3) ng/mL. Conclusions: The prevalence of vitamin D deficiency among healthy Saudi men is between 28% to 37%. Vitamin D deficiency among young and middle age Saudi Arabian males could lead to serious health consequences if the issue is not urgently addressed.

Lack of MERS Coronavirus Neutralizing Antibodies in Humans, Eastern Province, Saudi Arabia

We used a lentiviral vector bearing the viral spike protein to detect neutralizing antibodies against Middle East respiratory syndrome coronavirus (MERS-CoV) in persons from the Eastern Province of Saudi Arabia. None of the 268 samples tested displayed neutralizing activity, which suggests that MERS-CoV infections in humans are infrequent in this province.

Vitamin D deficiency and rickets in the Eastern Province of Saudi Arabia

Abstract Background: Nutritional rickets remains prevalent in many developing countries, despite the availability of ample sunlight. The aim of this study was to investigate the clinical features and chemical pathology in a group of children with rickets and to compare them with a control group. Subjects and Methods: In a case-control study over a 1-year period (March 2004 to February 2005), children clinically diagnosed with rickets (n=61) were age- and sex-matched with controls (n=58). In addition to routine chemical pathology, 25 (OH) vitamin D3 and parathormone (PTH) were determined. Controls were children without clinical rickets attending hospital for other blood investigations. Results: The mean age of children with rickets was 14.8 mths and of controls was 16.5 mths. Mean (SD) body mass index of the children with rickets [16.8 (1.86)] was not significantly different from that of the controls [17.02 (3.16)]. Mean (SD) head circumference of rachitic children [45.41 (3.64) cm] was greater than that of controls [44.39 (5.07) cm, p=0.03]. Eighty per cent of the children with rickets were breastfed compared with 67% of controls. Thirty per cent of children with rickets were hypocalcaemic vs <7% of controls, 89% had phosphorus values <1.5 mmol/L vs 34.5% of controls and 75% had alkaline phosphatise levels >500 IU/L vs 28% of controls. Seventy-five per cent of children with rickets had serum 25 (OH) D3 <20 nmol/L vs 25% of controls. Mean (SD) PTH level was 23.59 (19.03) pmol/L in the rachitic group and 1.9 (1.05) pmol/L in controls (p<0.05). Lack of exposure to sunlight was recorded in 90% of the children with rickets and in 37% of the controls. Conclusion: Apparently healthy children living in areas where rickets is prevalent have risk factors for rickets and a small proportion will have evidence of biochemical rickets.

Molecular Characterization of Glucose-6-Phosphate Dehydrogenase Deficiency in the Eastern Province of Saudi Arabia

Abstract The level of activity of the enzyme glucose-6-phosphate dehydrogenase (G6PD) was determined in 154 unrelated Saudi males and females with G6PD deficiency who were residing in the Eastern Province of Saudi Arabia. DNA was extracted from blood samples and analyzed for known G6PD mutations by polymerase chain reaction (PCR) and restriction fragment length polymorphism techniques. Two different polymorphic mutations were identified which accounted for 90% of the samples analyzed. Of 114 G6PD-deficient males, 96 had G6PD Mediterranean, nine had African deficient variant G6PD A- and in nine the mutation has not been identified. Of the 40 G6PD-deficient females, 34 were homozygous for the G6PD Mediterranean mutation and six were genetic compound, G6PD Mediterranean/G6PD A-. The data indicate that the G6PD Mediterranean mutation is the most common (84%) in the Eastern Province, followed by G6PD A-(5.8%). Seventy one subjects who suffered from favism were found to carry the Mediterranean mutation.

Sickle cell disease in Saudi Arabia: the phenotype in adults with the Arab-Indian haplotype is not benign.

Sickle cell disease (SCD) in Saudi patients from the Eastern Province is associated with the Arab‐Indian (AI) HBB (β‐globin gene) haplotype. The phenotype of AI SCD in children was described as benign and was attributed to their high fetal haemoglobin (HbF). We conducted a hospital‐based study to assess the pattern of SCD complications in adults. A total of 104 patients with average age of 27 years were enrolled. Ninety‐six per cent of these patients reported history of painful crisis; 47% had at least one episode of acute chest syndrome, however, only 15% had two or more episodes; symptomatic osteonecrosis was reported in 18%; priapism in 17%; overt stroke in 6%; none had leg ulcers. The majority of patients had persistent splenomegaly and 66% had gallstones. Half of the patients co‐inherited α‐thalassaemia and about one‐third had glucose‐6‐phosphate dehydrogenase deficiency. Higher HbF correlated with higher rate of splenic sequestration but not with other phenotypes. The phenotype of adult patients with AI SCD is not benign despite their relatively high HbF level. This is probably due to the continued decline in HbF level in adults and the heterocellular and variable distribution of HbF amongst F‐cells.

Validation of a reverse-hybridization StripAssay for the simultaneous analysis of common α-thalassemia point mutations and deletions

Abstract Background: α-Thalassemia is a worldwide disease and considered to be a major public health problem in countries within the so-called thalassemia belt. The complex genetics of α-thalassemias requires diagnostic methods with the capacity to screen rapidly and accurately for common causative mutations. Methods: We developed and validated a reverse-hybridization assay (Alpha-Globin StripAssay) for the rapid and simultaneous detection of 21 α-globin mutations: two single gene deletions (–α3.7; –α4.2), five double gene deletions [--MED; --SEA; --THAI; --FIL; –(α)20.5], αααanti-3.7 gene triplication, two point mutations in the α1 gene (cd 14 G>A; Hb Adana) and 11 point mutations in the α2 gene (initiation cd T>C; cd 19 –G; IVS1 –5nt; cd 59 G>A; Hb Quong Sze; Hb Constant Spring; Hb Icaria; Hb Pakse; Hb Koya Dora; polyA-1; polyA-2). Results: Reliable genotyping of recombinant mutant clones and reference DNA samples was achieved by means of two corresponding test strips presenting parallel arrays of allele-specific oligonucleotides. The entire procedure from blood sampling to the identification of mutations required less than 6 h, and hybridization/detection was manual or automated. The diagnostic potential of this Alpha-Globin StripAssay was carefully evaluated on 272 pre-typed samples in a multicenter validation study. In 96.14% of the cases, StripAssay typing was completely concordant with the reference methods. Conclusions: The Alpha-Globin StripAssay proved to be a fast, easy-to-perform and reliable screening method to identify >90% of α-globin mutations in endemic areas worldwide. Clin Chem Lab Med 2007;45:605–10.

Fetal hemoglobin in sickle cell anemia: genetic studies of the Arab-Indian haplotype.

Sickle cell anemia is common in the Middle East and India where the HbS gene is sometimes associated with the Arab-Indian (AI) β-globin gene (HBB) cluster haplotype. In this haplotype of sickle cell anemia, fetal hemoglobin (HbF) levels are 3-4 fold higher than those found in patients with HbS haplotypes of African origin. Little is known about the genetic elements that modulate HbF in AI haplotype patients. We therefore studied Saudi HbS homozygotes with the AI haplotype (mean HbF 19.2±7.0%, range 3.6 to 39.6%) and employed targeted genotyping of polymorphic sites to explore cis- and trans- acting elements associated with high HbF expression. We also described sequences which appear to be unique to the AI haplotype for which future functional studies are needed to further define their role in HbF modulation. All cases, regardless of HbF concentration, were homozygous for AI haplotype-specific elements cis to HBB. SNPs in BCL11A and HBS1L-MYB that were associated with HbF in other populations explained only 8.8% of the variation in HbF. KLF1 polymorphisms associated previously with high HbF were not present in the 44 patients tested. More than 90% of the HbF variance in sickle cell patients with the AI haplotype remains unexplained by the genetic loci that we studied. The dispersion of HbF levels among AI haplotype patients suggests that other genetic elements modulate the effects of the known cis- and trans-acting regulators. These regulatory elements, which remain to be discovered, might be specific in the Saudi and some other populations where HbF levels are especially high.

MOLECULAR BASES OF BETA-THALASSEMIA IN THE EASTERN PROVINCE OF SAUDI ARABIA

β-thalassemia is a group of heterogeneous recessive disorders common in many parts of the world. Al-Qatif and Al-Hassa oases in the Eastern Province of Saudi Arabia are regions known for high frequency of these disorders. Using two molecular methods, based on multiplexing-amplification refractory system and reverse hybridization principles, the spectrum of β-thalassemia in the region was studied. Sixty-nine subjects with known β-thalassemia disease and volunteers with high hemoglobin A2(HbA2) and low mean corpuscular volume (MCV) were included in this study. Ten mutations were detected in 91% of the subjects under study. Six of these mutations had previously been observed while the other four mutations are reported here for the first time. In addition, four of the mutations accounted for 76.8% of the subjects studied. IVSII-1 (G > A), IVSI-5 (G > A), and codon 39 (C > T) mutations were found to be the most frequent. However, the frequencies of different mutations reported here are slightly different from those reported earlier. A number of these mutations were also found in the neighboring countries, which can be explained in terms of gene flow.

Spectrum of α-Thalassemia Mutations in Transfusion-Dependent β-Thalassemia Patients from the Eastern Province of Saudi Arabia

Both α- and β-thalassemia (α- and β-thal) are highly prevalent in the population of the Al-Qatif and Al-Ahsa regions in the Eastern Province of Saudi Arabia. This study provides a more precise picture of the α-thal mutations prevalent in 104 transfusion-dependent β-thal patients in the Eastern Province. Detection of α-thal mutations was carried out using the α-globin StripAssay kit. A total of 12 α-thal mutations (21 genotypes) were identified in 33.7% of the chromosomes (46 patients). The heterozygous and homozygous –α3.7 (α+) deletion mutations were the most prevalent in the β-thal patients (21.7%). We identified three α0 deletions [– –MED, – –FIL and –(α)20.5] that have not been previously reported for the population of Saudi Arabia. The seven point mutations identified in the β-thal patients were: codon 14 [TGG>TAG (α1)], codon 59 [GGC>GAC (α1)] (Hb Adana), polyadenylation signal site (polyA1) [AATAAA>AATAAG (α2)], codon 142 [TAA>TCA (α2)] (Hb Koya Dora), codon 59 [GGC>GAC (α2)] (Hb Adana), initiation codon [ATG>ACG (α2)] and the αααanti 3.7 gene triplication. The Hb Koya Dora mutation occurred at the highest frequency (15.38%). Comparison of the clinical phenotype of β-thal patients, with and without an α-thal mutation, showed that patients with β-thal alone had a significantly elevated level of alanine transaminase (ALT) (mean 72.5 IU/L) and aspartate transaminase (AST) (mean 71.8 IU/L) (p <0.005). In addition, the β-thal patients without an α-thal mutation had a higher percentage of osteoporosis (16.6%), fractures (12.5%), and splenectomies (58.3%). This confirms previous data that the co-inheritance of α-thal in β-thal patients results in the amelioration of the clinical phenotype of β-thal patients. Moreover, the high frequency of α- and β-thal in the Eastern Province of Saudi Arabia and their coinheritance, necessitates the inclusion of α-thal testing in the current pre marital testing program to highlight the risk to the offspring of affected individuals.

A comparative study of glycosylated haemoglobin level in the arabian camel (Camelus dromedarius) during different seasons

1. The extent of haemoglobin glycosylation from 60 camels has been determined (4.39%) in blood samples drawn during winter. 2. Phosphate (9.45 mg/dl), DPG (2.9 mumol/ml) and glucose (138 mg/dl) levels were also recorded. 3. In addition the P50 at pH 7.4 was measured (22.8 Torrs). 4. The data obtained compared with human blood levels and with levels reported for camels during summer sampling. 5. Despite the fact that camels have higher blood glucose levels than humans, the extent of glycosylation is much less in camel blood than in human blood.