Competitive Allele-specific Polymerase Chain Research Articles

#2436 Genetic variability in rosuvastatin metabolism explains rhabdomyolysis and consequent acute renal failure

Abstract Background and Aims Low density lipoprotein cholesterol is an independent risk factor for atherosclerotic cardiovascular disease. Rosuvastatin is one of the most frequently prescribed statins and also one of the most frequent causes of rhabdomyolysis with consequent acute renal failure (ARF). Risk factors for statin induced rhabdomyolysis, i.e. the type of statin and its dose, patient's age, kidney and liver function, gender and concurrent treatment with cytochrome P450 (CYP) inhibitors, should be considered at the time of statin prescription. Single nucleotide polymorphisms (SNPs) in genes coding the transport proteins (SLCO1B1, ABCG2) and CYP2C9, catalysing rosuvastatin oxidation, may lead to decreased protein function leading to accumulation of plasma rosuvastatin which increases the risk of rhabdomyolysis. Herewith we present a case of a female patient admitted to our department due to rhabdomyolysis and ARF with the aim of alerting against uncritical high dose rosuvastatin prescribing and of pointing out the role of genetic variability in drug metabolizing enzymes and transporters (DMET) in rosuvastatin side effects. Method a 79-years old Caucasian woman admitted to our department due to rhabdomyolysis and ARF was genotyped for polymorphisms in DMET genes coding for CYP2C9 (rs1799853, rs1057910, rs28371686, rs28371685), SLCO1B1 (rs4149056, rs2306283) and ABCG2 (rs2231142) using competitive allele specific polymerase chain reaction (KASPar). Results Presented patient suffered from an acute myocardial infarction in October 2023. She was treated with percutaneous coronary intervention, antiaggregation therapy and hypolipidemic therapy (rosuvastatin 40 mg/ezetimibe 10 mg). Her creatinine was 55 μM (eGFR 61 ml/min) at the time of statin prescription. Several months later she was admitted septic with myoglobin >50.000 μg/L and creatinine approximately 1600 μM. Infection was treated with piperacillin/tazobactam. Myoglobin was removed with Theranova dialyzer. The patient was dismissed home two weeks later with creatinine 230 μM. As potential patient's risk factors for rhabdomyolysis we considered high dose of rosuvastatin, patient's higher age and slower rosuvastatin disposition due to SNPs in DMET. Sepsis may have been an additional contributory factor. Genotyping revealed polymorphisms in all three genes involved in rosuvastatin metabolism and transport: CYP2C9, SLCO1B1 and ABCG2 (Table 1). Two genotypes resulted in the phenotypes with slower rosuvastatin metabolism, probably leading to gradual accumulation of plasma rosuvastatin, which may have manifested in rhabdomyolysis that contributed to ARF. Heterozygous CYP2C9*2 and *3 carriers have, in comparison to the wild type carriers, approximately 30% and 80% slower rosuvastatin metabolism, respectively. Heterozygous ABCG2 c.421C>A carrier state may also contribute slightly to rosuvastatin accumulation. Furthermore, the potential interaction with inflammation should not be overlooked, as inflammation may have a major effect on drug metabolism and transport through downregulation of CYP enzymes as well as drug transporters. If genotypes of the respective DMET genes were known in advance, high dose rosuvastatin could have been avoided despite relatively good kidney function at the time of rosuvastatin prescription. Conclusion Statins should be prescribed with caution and their dose adapted to the risk factors that should always be checked for at the time of statin prescription. We recommend periodical surveillance of serum creatinine, eGFR, urine protein to creatinine ratio, liver tests, creatine kinase and myoglobin in patients treated with high dose statins. Furthermore, SLCO1B1, ABCG2 and CYP2C9 genotyping before rosuvastatin prescription would enable insight into its metabolism. Genotype information could lead to more cautious statin prescribing, especially in the presence of other factors, such as infection or concomitant drug treatment that may modify the activity of DMET. In the case of chronic kidney disease drug dosing should be appropriately adjusted in accordance with drug's Summary of product characteristics and KDIGO guidelines.

Protective and pathogenic role of collagen subtypes genes COL4A3 and COL4A4 polymorphisms in the onset of keratoconus in South-Asian Pakistani cohort

Collagen sub-types have an important role in corneal structure and are reported to be an important genetic predictor for keratoconus (KC) development, therefore we assessed the association of collagen subtypes by screening non-synonymous polymorphisms of COL4A3 and COL4A4 in South-Asian (Pakistani) patients. MethodsA total of 257 KC sporadic cases, gender and ethnicity matched 253 control individuals were screened for three non-synonymous single nucleotide polymorphisms (SNPs) rs55703767and rs10178458 in COL4A3 and rs2229814 and one synonymous SNP rs2228555 in COL4A4. The genotyping was done by Competitive Allele specific polymerase chain reaction (PCR) and the data were analyzed statistically. ResultsAmong the studied SNPs, the COL4A3 rs55703767 GT genotype (dominant model (DM): odds ratio (OR) = 0.243, (95 %CI) = 0.16–0.36, p=>0.0001), and allele-G (OR = 0.35, 95 %CI = 0.26–0.48, p < 0.000)), showed protective association against KC development. While COL4A3 rs10178458 CT genotype (DM: OR = 2.11(95 %CI = 1.16–3.85), COL4A4 rs2229814 TT genotype (RM: OR = 147.778(95 %CI = 20.401–1070.439), (p > 0.05) and allele-T (OR = 2.351(95 %CI = 1.826–3.028), (p > 0.05); COL4A4 rs2228555 AG genotype (DM: OR = 2.370(95 %CI = 1.594–3.524) (<0.0001) and GG genotype (RM: OR = 2.347(95 %CI = 1.587–3.472), (p < 0.0001); and allele-G (OR = 2.024(95 %CI = 1.577–2.597), (p > 0.0001) were observed to be disease associated. ConclusionCOL4A3 rs10178458 and COL4A4 SNPs rs2229814 and rs2228555 were found to be pathogenic for KC, whereas COL4A3 rs55703767 was found to play a protective role against KC development in South-Asian (Pakistani) Cohort.

Disease Resistant Citrus Breeding Using Newly Developed High Resolution Melting and CAPS Protocols for Alternaria Brown Spot Marker Assisted Selection

Alternaria alternata is a fungus that causes a serious disease in susceptible genotypes of citrus, particularly in mandarins. The Alternaria citri toxin (ACT) produced by the pathogen induces necrotic lesions on young leaves and fruits, defoliation and fruit drop. Here, we describe two methods of marker-assisted selection (MAS) that could be used for the early identification of Alternaria brown spot (ABS)-resistant mandarin hybrids. The first method is based on a nested PCR coupled to high resolution melting (HRM) analysis at the SNP08 locus, which is located at 0.4 cM from the ABS resistance locus, and was previously indicated as the most suitable for the selection of ABS-resistant hybrids. The method was validated on 41 mandarin hybrids of the CREA germplasm collection, and on 862 progenies generated from five crosses involving different susceptible parents. Four out of five populations showed Mendelian segregation at the analyzed locus, while a population involving Murcott tangor as male parent showed distorted segregation toward the susceptible hybrids. The second method is based on a cleaved amplified polymorphic sequences (CAPS) marker that was developed using the same primers as the nested PCR at the SNP08 locus, coupled with BccI restriction enzyme digestion. To verify the reliability of the two genotyping methods, in vitro leaf phenotyping was carried out by inoculating A. alternata spores onto young leaves of 101 hybrids, randomly chosen among the susceptible and resistant progenies. The phenotyping confirmed the SNP08 genotyping results, so the proposed method of selection based on HRM or CAPS genotyping could be routinely used as an alternative to KBioscience competitive allele specific polymerase chain reaction (KASPar) single nucleotide polymorphism (SNP) genotyping system to improve citrus breeding programs. While the study confirmed that the SNP08 marker is a reliable tool for MAS of new citrus hybrids with different genetic backgrounds, it also identified a small group of genotypes where the resistance mechanism requires further investigation.

Association between single nucleotide polymorphisms in prospective genes and susceptibility to ankylosing spondylitis and inflammatory bowel disease in a single centre in Turkey.

To establish the prevalence of the single nucleotide polymorphisms (SNPs) of endoplasmic reticulum aminopeptidase 1 (ERAP1), IL-23 receptor (IL-23R), signal transducer and activator of transcription 3 (STAT-3) and Janus kinase 2 (JAK-2) in ankylosing spondylitis (AS) and inflammatory bowel disease (IBD) in a Turkish population. A total of 562 subjects who presented at the Ankara University internal medicine departments of rheumatology and gastroenterology outpatient clinics were recruited in this study, including 365 patients with AS, 197 patients with IBD and 230 healthy controls. ERAP1, IL-23R, STAT-3 and JAK-2) were genotyped in competitive allele-specific polymerase chain reactions. The ERAP1 (rs26653) polymorphism was found to increase the disease risk in patients with AS and IBD compared with the control group (p=0.02 and p=0.01, respectively). In addition, this polymorphism revealed a significant relationship with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Bath AS Functional Index (BASFI) in patients with AS (r=0.829, p < 0.001 and r=0.731, p < 0.001, respectively). The ERAP1 gene polymorphism might be a risk factor in the pathogenesis of AS and IBD. In contrast, IL-23R gene polymorphisms may serve a protective role in AS and IBD.

Relationship of genetic factors with development of aortic dissection and aneurysm.

This study aims to investigate the relationship between the development of aortic dissections and aneurysms with the polymorphisms of angiotensin converting enzyme gene, methylenetetrahydrofolate reductase gene, plasminogen activator inhibitor-1 gene, and nitric oxide synthase gene. Between April 2009 and July 2014, 38 patients with aortic dissections (28 males, 10 females; mean age 55.1±10.7 years; range, 30 to 78 years) and 67 patients with aortic aneurysms (57 males, 10 females; mean age 63.0±11.4 years; range, 31 to 82 years) were included in this cross-sectional study. The control group consisted of 60 healthy volunteers (41 males, 19 females; mean age 56.3±11.2 years; range, 30 to 82 years) without an aortic aneurysm or dissection, as assessed by thoracoabdominal computed tomography. The prespecified four genes were genotyped with competitive allelespecific polymerase chain reaction. The aortic dissection group had higher nitric oxide synthase-3 (4b/4b) expression levels, compared to the control group. The aortic aneurysm group had also higher nitric oxide synthase-3 (4b/4a) expression levels, compared to the control group. Compared to the control group, a higher rate of angiotensin converting enzyme I/D gene polymorphism was detected in the aneurysm group, while higher D/D polymorphism rates were found in the dissection group; although not statistically significant. Our study results suggest that the nitric oxide synthase-3 intron 4b/4b and nitric oxide synthase-3 intron 4b/4a gene polymorphisms can be used as a predictor of aortic dissection and aneurysm development.

Vitamin D status, serum lipid concentrations, and vitamin D receptor (VDR) gene polymorphisms in Familial Mediterranean fever.

Vitamin D (VitD) is critical for the regulation of inflammatory processes, and VitD deficiency has been linked to several chronic inflammatory disorders. We aimed to investigate the concentrations of serum 25(OH)D3, lipid parameters, and three known VDR polymorphisms (BsmI, FokI, and TaqI) in patients with Familial Mediterranean fever (FMF), an autosomal recessive autoinflammatory disease. The study included 123 FMF patients and 105 controls. Seventy patients had no attack (group 1), 30 had 1-2 attacks (group 2), and 23 had 3 or more attacks (group 3) within last three months. Serum 25(OH)D3 concentrations were determined using liquid chromatography-tandem mass spectrometry. BsmI, FokI, and TaqI polymorphisms were analyzed by a competitive allele specific polymerase chain reaction assay (KASPar). Serum lipid parameters were measured with enzymatic colorimetric methods. 25(OH)D3 concentrations were lower in FMF patients compared to controls (p < 0.001). No difference was observed in 25(OH)D3 concentration between groups 1, 2, and 3. The distributions of FokI and TaqI genotypes were not significantly different between FMF patients and controls. There was a significant difference in the distribution of AA BsmI genotype between male FMF patients and male controls. Increased concentrations of triglycerides (p = 0.012) and decreased concentrations of high-density lipoprotein cholesterol [HDL-C] (p = 0.006) were found in FMF patients compared to controls. Although lower 25(OH)D3 concentrations were observed in FMF patients versus controls, no association was determined between FMF attack frequency and 25(OH)D3 concentrations. We showed that the AA genotype of BsmI polymorphism is associated with FMF in males but not in females. The effects of decreased HDL-C and increased triglyceride concentrations on cardiovascular events in FMF patients should be further investigated.

Receptor activator of nuclear factor kappa-B gene polymorphisms in Iranian periodontitis and peri-implantitis patients.

Peri-implantitis and periodontitis are inflammatory and infectious diseases of implant and tooth-supporting tissues. Recently, the role of gene polymorphisms of immune response components in the relevant pathogenesis has been investigated. The present study was the first to evaluate the relationship between two known single nucleotide polymorphisms (SNPs) of the receptor activator of nuclear factor kappa-β (RANK) gene (rs3018362 and rs35211496) in chronic periodontitis and peri-implantitis patients in an Iranian population. Eighty-one periodontally healthy patients, 38 patients with peri-implantitis, and 74 patients with chronic periodontitis were enrolled in this study. DNA was extracted from blood arm vein samples by using Miller's salting out technique according to the manufacturer's instructions given in the extraction kit. The concentration of DNA samples was measured using a spectrophotometer. The genetic polymorphisms of the RANK gene were evaluated using a competitive allele specific polymerase chain reaction (KBioscience allele specific PCR) technique. Differences in the frequencies of genotypes and alleles in the diseased and healthy groups were analyzed using chi-squared statistical tests (P<0.05). Analysis of rs35211496 revealed statistically significant differences in the expression of the TT, TC, and CC genotypes among the three groups (P=0.00). No statistically significant difference was detected in this respect between the control group and the chronic periodontitis group. The expression of the GG, GA, and AA genotypes and allele frequencies (rs3018362) showed no statistically significant difference among the three groups (P=0.21). The results of this study indicate that the CC genotype of the rs35211496 RANK gene polymorphism was significantly associated with peri-implantitis and may be considered a genetic determinant for peri-implantitis, but this needs to be confirmed by further studies in other populations.