Prevalence of CYP2C19*2 carriers in Saudi ischemic stroke patients and the suitability of using genotyping to guide antiplatelet therapy in a university hospital setup

Objectives To mitigate the incidence of recurrent stroke in patients, dual antiplatelet therapy comprising aspirin and clopidogrel is usually administered. Clopidogrel is a prodrug and its bioactivation is catalyzed by cytochrome P450 (CYP)2C19. The main objective of this work was to determine the prevalence of CYP2C19*2 carriers in Saudi ischemic stroke patients and assess the suitability of using genotyping to guide antiplatelet therapy in a university hospital setup. Methods This prospective (2018–2019) study was conducted on 256 patients (age 61 ± 12.5) clinically diagnosed with ischemic stroke who were genotyped using Spartan RX CYP2C19 assay. Results From the total patient group (256), upon admission, 210 patients were prescribed either aspirin, clopidogrel or dual antiplatelet therapy. Of the 27 patients with the CYP2C19*2 allele who were prescribed clopidogrel (18) or dual antiplatelet therapy (9), only 21 patients could be followed up for a period of six months post stroke event, in addition to 21 age- and sex-matched patients with the normal allele. The CYP2C19*2 allele carriers had a statistically significant increased risk of recurrent stroke compared to patients carrying the normal allele. Conclusions This study shows the suitability of using genotyping to guide antiplatelet therapy in ischemic stroke patients in a clinical setting.

COL1A1, COL4A3, TIMP2 and TGFB1 polymorphisms in cervical insufficiency

Objectives To investigate the association between selected single nucleotide polymorphisms (SNPs) with cervical insufficiency and its relationship with obstetric history. Methods Twenty-eight women with cervical insufficiency (case group) and 29 non-pregnant women (control group) were included. The SNPs sequenced included rs2586490 in COL1A1, rs1882435 in COL4A3, rs2277698 in TIMP2, and rs1800468 in TGFB1. Results We found a higher frequency of the normal allele in the control group (65.5%) and the homozygous mutated genotype in the case group (64.3%) for rs2586490 in COL1A1 (p=0.023). An unplanned finding in the cervical insufficiency group was a higher gestational age of delivery (median≥38 weeks) in the mutated allele than in the wild-type genotype (median of 28.2 weeks) for rs2857396, which is also in the COL1A1 gene (p=0.011). Conclusions The findings of the present study corroborate the hypothesis that cervical insufficiency has a genetic component and probably involves genes encoding proteins in the extracellular matrix, in addition to inflammatory processes.

A study of CBS gene polymorphism, plasma H2S levels and their association in type-2 diabetes mellitus

Background: Hydrogen Sulphide (H2S), in recent years, is getting significant attention, as more evidences are emerging about its diverse biological roles. There are evidences of H2S having anti-inflammatory, neuro-modulator, vasodilator, anti-apoptotic and mitochondrial protective roles in various tissues. Among different tissues, β-cells of pancreas, according to some recent studies, get significantly affected by the imbalance in H2S homeostasis, leading to β-cell dysfunction and Diabetes Mellitus (DM). Cystathionine- β-synthase (CBS) enzyme is involved in the synthesis of H2S from cysteine in various tissues. Among various possible mutations in the CBS gene, a particular 833T-C mutation, has been found to be associated with various diseases. Aims and Objectives: The present study was aimed to determine the extent of abnormality of H2S homeostasis in type-2 DM patients, and to find out presence and association (if any) of 833T-C mutation in CBS gene, in the patients of type-2 DM, in comparison to healthy control subjects, in the Indian population. Materials and Methods: A cross sectional study was done with 40 clinically and biochemically diagnosed DM type II patients attending OPD of Endocrinology department of NRS Medical College & Hospital, Kolkata, and 40 age and gender matched non-diabetic control subjects. DNA was isolated from EDTA blood of all the study subjects, PCR done and results compared. Plasma H2S was measured by the N,N-dimethyl-p-phenylene-diamine method. Plasma glucose and serum insulin were measured by standardized commercial kits. Results: Our study found the plasma H2S levels in the patients of type II DM to be significantly higher(P<0.001) than the control subjects. The results also found significant positive correlation between plasma H2S level with fasting serum Insulin level (P<0.001) and fasting plasma glucose level (P<0.001) in the diabetic patients. Among 40 DM patients, only two were heterozygous for the mutation, and had both mutated allele (242bp) and normal allele (174bp). Rest of the patients and all the control subjects were homozygous for the normal allele (174bp). This marginal difference in the incidence of mutated allele was not found to be statistically significant. Conclusion: our study shows significant association of H2S dys-regulation with the type-2 Diabetes Mellitus in Indian population. The marginal but insignificantly higher incidence of 833T-C mutation in CBS gene, found in our study, warrants further research with higher number of study population, to more conclusively infer about the role of this mutation in the pathogenesis of type-2 DM.

Genetic Screening of Deficiency of Uridine Monophosphate Synthase in Holstein Freisian Crossbred Cattle

Fifty Holstein Friesian (H.F) crossbredcattle were screened for Deficiency of Uridine Monophosphate Synthase (DUMPS) using PCR-RFLP. Blood samples were collected from jugular veins in 2 ml capacity vaccutainers containing 2 mg/ml (K2 EDTA). DNA was isolated from the blood samples by using whole blood extraction kit. PCR was performed for amplification of polymorphic region of Uridine Monophosphate Synthase (UMPS) gene (108 bp) on bovine chromosome 1. The PCR products of 108 bp were digested with AvaI endonuclease enzyme. The normal allele in unaffected cattle produced three fragments of 53 bp, 36 bp and 19 bp. No animal was found carrier for UMPS gene. The genotype frequency of normal individuals and the gene frequency of normal allele were found to be one.

ID: 1048 A novel nonsense mutation in the CYP21A2 gene of a Vietnamese patient with congenital adrenal hyperplasia

Inactivating mutations in the CYP21A2 gene which encodes the protein involved in steroid synthesis have been reported in the patients with congenital adrenal hyperplasia (CAH). An infant who diagnosed with the severe phenotype of CAH such as increasing testicular volume, elevating of 17-hydroxyprogesteron, testosterone and progesterone and his family were subjected for genetic studies. Initially, we used PCR and direct sequencing to screen mutations in the CYP21 gene in the proband and his family. We identified a novel nonsense mutation c.374C>G predicts a substitution of serine for a stop codon at codon 125 (p.S125*) within exon 3 in the proband. However, the inheritance pattern of the mutation was not consistent with disease causation because of a heterozygous mutation carrier in father and sibling, wild-type alleles in mother but mutant alleles in proband. This inspired us to find deletions of exon using multiplex ligation-dependent probe amplification (MLPA) assay. In the profiles of MLPA electropherogram, the proband had a large deletion in exon 3, but his mother did not have. It means that the proband inherited a normal allele from his mother and a mutant allele from his father, but the deletion of a normal allele occurred in the proband. Therefore, mutation c.374C>G (p.S125*) in exon 3 in the proband is considered as a heterozygous deletion mutation. In addition, a large deletion in exon 1 in the maternal allele in the proband is observed. Taking together, the proband carried a nonsense mutation accompanied with two deletions in exon 1 and exon 3 in the CYP21A2 gene affect the CAH phenotype severity. These mutations also expand the CYP21A2 mutation spectrum in CAH disorder. This case also highlights the need of caution when interpreting results of molecular genetics and biochemical testing during genetic counseling.

Evaluation Of Slovak Winter Wheat Quality In Terms Of Puroindoline Genes

The grain hardness of 100 current and 24 old superior Slovak winter wheat cultivars was studied at molecular level. Using polymerase chain reactions (PCRs), normal and null alleles of both puroindoline Pina and Pinb genes were identified. Three different genotypes were found: 1) normal allele of both genes (dominant wild type with soft endosperm) − Pina-D1a/Pinb-D1a; 2) normal allele of the Pina gene and null allele of the Pinb gene – Pina-D1a/Pinb-D1b; and 3) null allele of the Pina gene and normal allele of the Pinb gene Pina-D1b/Pinb-D1a. No Slovak current as well as old wheat cultivar had together null allele of both puroindoline genes. The frequencies of wild-type Pinb-D1a and null Pinb-D1b allele in current cultivars were 62.0% and 38.0%, respectively, whilst in old cultivars, 8.3% and 91.7%, respectively. Regarding null allele Pina-D1b of puroindoline Pina gene, only in Rheia current cultivar, one was found. All other cultivars had wild-type Pina-D1a allele. Alacris, Alana, Axis, Balada, Blava, Bona Dea, Bruta, Charger, Hana, Ilona, IS Karpatia, Ludwig and Sulamit current cultivars were selected as donors of the null Pinb-D1b allele for molecular breeding in order to improve the grain hardness as important wheat quality trait. Statistically significant correlations between null Pinb-D1b allele and grain size as well as colour were found. In comparison with wild type, cultivars with this null allele have paler and longer grain with higher length-to-width ratio and lighter grain colour.

Toxicity of azathioprine: why and when? analysis of the prevalence of polymorphism in Joinville, SC, Brazil

CONTEXT: The use of thiopurine drugs such as azathioprine and 6-mercaptopurine has become quite common in the treatment of inflammatory bowel disease, transplantation and acute leukemias. Despite their effectiveness, these drugs are capable of causing drug-induced toxicity with the risk of death by myelosuppression. It is now known that these complications occur because of genetic polymorphisms of the thiopurinemethyltransferase (TPMT) enzyme, responsible for its metabolism. OBJECTIVE: To assess the prevalence of thiopurine methyltransferase polymorphisms in the population of Joinville, SC, Brazil. METHODS: We analyzed the frequency of four main allelic variants of the TPMT gene in 199 blood donors from Joinville, from February to April 2010. RESULTS: The normal allele ("wild-type") was found in 93.9% of subjects studied. TPMT variants were detected in 12 subjects (6.03%). CONCLUSIONS: From this study, it was estimated at 6% the risk of toxicity by the administration of azathioprine and 6-mercaptopurine to patients in Joinville.