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PubMed2003

[Genetic background predisposing the drug-induced long QT syndrome].

Molecular and cellular mechanisms underlying the QT prolongation have been elucidated largely because of the recent understanding of the generation of the congenital forms of QT prolongation; i.e., the long QT syndrome. To date, at least 7 different genes that modulate cardiac ion channels were identitied to be associated with the syndrome. In the clinical setting, the drug-induced long QT syndrome is more frequently seen and therefore important. We found several mutations as well as an SNP specific among the Japanese population in probands referred to as the secondary long QT patients, including the drug-induced cases. These findings raised the potential that there are also predisposing risk factors at patient's side.

Cation Transport Proteins↗
PubMed2001

The R100Q mutation of the GABA(A) alpha(6) receptor subunit may contribute to voluntary aversion to ethanol in the sNP rat line.

We have investigated the GABA(A) alpha(6) subunit molecular composition in two rat lines selectively bred for high or low ethanol preference and consumption, namely Sardinian alcohol-preferring (sP) and Sardinian non-alcohol-preferring (sNP) rats, which have been bred at the University of Cagliari, Italy, since 1981. A total of 27 sP, 22 sNP and 25 control rats belonging to five other different strains, were studied by direct sequencing and amplification refractory mutation system analysis. Among the sNPs, only one was found to be normal, 11 heterozygotes, and 10 homozygotes for the G-->A substitution in codon 100, the same R100Q point mutation previously described in Alcohol Non Tolerant rats, while no other animal showed any mutated allele. Pharmacological studies have extensively demonstrated that this substitution in the mature peptide changes the benzodiazepine-insensitive receptor to a sensitive one. In order to test the functional significance of this mutation in native cerebellar GABA(A) receptors, selective breeding from Q/R rats was employed to obtain a sufficient number of R/R homozygotes. Xenopus laevis oocytes were then injected with cerebellar synaptosomes extracted from Q/Q, R/Q and R/R sNP rats. Consistently, utilizing the two-electrode voltage-clamp technique, GABA-evoked currents mediated by GABA(A) receptors containing the mutated alpha(6) subunit were potentiated by diazepam with about a two-fold increased potency, as compared to receptors containing the wild-type, benzodiazepine-insensitive alpha(6) subunit. Our data show for the first time that a mutated GABA(A) alpha(6) receptor subunit segregates in a rat line which voluntarily avoids alcohol consumption, and further support a possible involvement of the GABA(A) receptor containing a mutated alpha(6) subunit in the genetic predisposition to alcohol preference.

Alcohol Drinking↗
PubMed2006

Congenital disorder of glycosylation type Ia: searching for the origin of common mutations in PMM2.

Congenital Disorders of Glycosylation (CDG) are a group of recessive genetic disorders characterized by hypoglycosylation of glycoproteins. CDG-Ia, the most common type, is caused by mutations in the PMM2 gene, coding for a phosphomannomutase (PMM2; EC 5.4.2.8). The mutational spectrum of PMM2 comprises more than 80 different mutations but one of them, R141H, is particularly interesting due to its high frequency among CDG-Ia patients worldwide. In contrast, other mutations are ethnically or geographically restricted, such as D65Y which is only found in patients of Iberian ancestry. In the present study a population genetic approach was used in an attempt to clarify the origins of two important disease causing mutations: R141H and D65Y. Based on SNP and STR genotypic analysis, we ascertained an association between the R141H substitution and a particular haplotype, suggesting a common origin for all the mutated chromosomes. Similar results were found for D65Y, although the associated haplotype was different from that of R141H, suggesting independent origins for these two mutations. Our results enable us to infer an Iberian origin for the D65Y mutation.

Carbohydrate Metabolism, Inborn Errors↗
PubMed2004

[NOD2/CARD15 mutations and genotype-phenotype correlations in patients with Crohn's disease. Hungarian multicenter study].

UNLABELLED: Recently mutations of the NOD2/CARD15 gene were identified as genetic markers for Crohn's disease (CD). It has also been suggested that the presence of mutation may influence the phenotype of the disease. The aim of this study was to determine the frequency of common NOD2/CARD15 mutations in Hungarian Crohn's patients. PATIENTS AND METHODS: DNA was obtained from 142 pts with Crohn's disease (70 male and 72 female, mean age: 36.2 yrs) and of 115 healthy subjects. Clinical data were obtained by filling in a questionnaire by the physician. DNA was screened for possible mutations by denaturing HPLC (WAVE Nucleic acid fragment analysis systems, Cheshire, UK) using published primers (Lesage et al, Am J Hum Gen 2002) for SNP's 8, 12, and 13. Mutations were then confirmed by direct sequencing on a ABI Prism 310 Genetic Analyzer (Perkin Elmer; Norwalk, USA). RESULTS: Mutations of NOD2/CARD15 were significantly more frequent in patients (n = 42, 29.6%) than in controls (11.3%, p = 0.0007, OR = 3.3, 95% CI = 1.7-6.5). R702W and 3020insC mutations were significantly more common in IBD compared to controls (4.3% and 2.6%); 18 patients had the R702W mutation (12.7%, p = 0.001, 13 homozygous, one homozygous for R703C) and 22 the 3020insC (15.9%, p = 0.001, 4 homozygous). 7 patients (4.9%) were heterozygous for the G908R, which was not different from the controls (4.3%). 5 patients were compound heterozygous. The allele frequency of R702W (11.6% vs. 4.3%, p = 0.0026, OR = 5.9, 95% CI: 2.3-14.9) and 3020insC (9.1% vs. 2.6% p = 0.004, OR = 7.6, 95% CI = 2.4-24.0) was significantly higher in Crohn's disease compared to the controls. Age at presentation was not different between carriers and non-carriers (26.7 +/- [SD] 10.3 yrs vs. 27.7 +/- 11.8 yrs). There was a tendency of ileal location to be more common in carriers of the mutation (40.5% vs. 29.0%), while colonic location was less frequent (16.7% vs. 44%). The presence of the mutation did not affect disease behaviour (carrier: inflammatory: 30.9%, stenosing: 26.2%, penetrating: 42.9%, non-carrier: inflammatory: 36%, stenosing: 27%, penetrating: 37%). Among the extraintestinal manifestations arthritis (30.1% vs. 47%, p = 0.05) and primary sclerosing cholangitis (0% vs. 9%, p = 0.047%) was significantly less frequent in carriers of the mutation. CONCLUSIONS: In concordance with European data we found a high number of NOD2/CARD15 R702W and 3020insC mutations in Hungarian patients with Crohn's disease. The G908R mutation was uncommon in Hungarian Crohn's patients. The presence of the mutation was associated with ileal but not with fibrostenosing disease and extraintestinal manifestations were less common in carriers of the mutation.

Adult↗
PubMed2004

Mutation analysis of five candidate genes in Chinese patients with hypospadias.

Hypospadias is the displacement of the urethral meatus from the tip of the glans to the ventral side of the phallus. During fetal development, SRY, SOX9, WT1, SRD5A2 and AR are important at different stages in the differentiation and development of the male genital system. Mutations in these genes impair masculinization and may be associated with hypospadias. In order to explore these possibilities, we employed polymerase chain reaction and direct sequencing to analyze the coding regions of these five genes in 90 Chinese hypospadias patients. We found a total of 16 different mutations in SRD5A2, AR and WT1 in 24 of these 90 patients. Seven mutations are novel. No mutation was found in SRY or SOX9. SNP V89L found in SRD5A2 was statistically significant between patients and controls. Our results indicated that mutations in SRD5A2, AR and WT1 were associated with hypospadias. In conclusion, mutations are frequently found in genes that control androgen action and metabolism, but are seldom found in genes active in the early phase of sex determination and differentiation. Mutations in AR, SRD5A2 or WT1 seem to be associated not only with hypospadias but also with micropenis.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMedDate not supplied

P53 gene status in patients with advanced serous epithelial ovarian cancer in relation to response to paclitaxel- plus platinum-based chemotherapy and long-term clinical outcome.

BACKGROUND: The aim of this retrospective study was to assess whether p53 gene status has any predictive or prognostic relevance in patients with advanced, poorly-differentiated serous epithelial ovarian cancer treated with paclitaxel- plus platinum-based chemotherapy. MATERIALS AND METHODS: The study was conducted on 46 patients who underwent surgery followed by paclitaxel- plus carboplatin-based chemotherapy. The tumor tissue samples were analyzed for p53 gene mutations. The median follow-up of survivors was 50.3 months. RESULTS: Twenty-three patients (50%) showed p53 mutations at exons 5 to 9. Sixteen (34.8%) patients had a polymorphism at codon 72 in exon 4 (SNP codon 72): 10 were Pro/Pro homozygous and 6 Pro/Arg heterozygous. Four polymorphic patients had a second mutation at exons 5 to 9. An inverse correlation was evidenced between the SNP codon 72 and mutations at exons 5 to 9, with the latter more frequently found in wild-type (Arg/Arg) codon 72 (19/30 versus 4/16, 63.3% versus 25.0%; p=0.03) cases. A clear trend for a higher response rate and longer progression-free and overall survival was observed in wild-type p53 and Pro/Pro polymorphic patients as compared to patients with mutant p53. CONCLUSION: The addition of paclitaxel to carboplatin does not appear to overcome the negative predictive and prognostic significance of p53 gene mutations in serous ovarian cancer. Nevertheless, the comprehensive analysis of p53 genotype, including the SNP codon 72, warrants further investigation in order to envisage individual responsiveness to cancer therapy.

Adult↗
PubMed2003

Molecular characterization of new polymorphisms at the beta2, alpha1, gamma2 GABA(A) receptor subunit genes associated to a rat nonpreferring ethanol phenotype.

Recent preclinical and clinical studies have indicated a possible involvement of the genes encoding for the GABA(A) receptor subunits alpha6, beta2, alpha1 and gamma2 in the genetic susceptibility to alcohol abuse. We have recently found an (R) to (Q) mutation in codon 100 of the alpha6 GABA(A) subunit, that segregated in a rat line selectively bred for its voluntary ethanol aversion, Sardinian alcohol nonpreferring (sNP), but not in their Sardinian alcohol preferring (sP) counterpart, selected for its ethanol preference. In the present study the molecular composition of other GABA(A) subunits (beta2, alpha1 and gamma2) were analyzed in order to further investigate the involvement of the GABA(A) receptors in the genetic predisposition to voluntary alcohol intake. Automated sequencing analysis indicated the presence of six new silent substitutions (289 T-->C in the beta2 gene; 115 G-->A in the alpha1 gene; 157 G-->A, 174 C-->T, 347 A-->G and 385 A-->T in the gamma2 gene), in sNP but not in sP rats. These polymorphisms were linked to the alpha6 R100Q mutation previously described in sNP rats. The strict association between the alpha6 point mutation and the new polymorphisms found in the beta2, alpha1 and gamma2 genes, demonstrate that such genes belong to the same cluster and are inherited together in the rat. These results sustain the synteny for these clusters between the rodent and human genomes, and suggest that mutated GABA(A) beta2, alpha6, alpha1 and gamma2 subunit genes might contribute to the expression of an ethanol nonpreferring phenotype in a rat line that voluntarily avoids alcoholic solutions.

Alcohol-Induced Disorders, Nervous System↗
PubMed1999

Mutation detection by denaturing DNA chromatography using fluorescently labeled polymerase chain reaction products.

A specialized form of ion-pair reversed-phase high-performance liquid chromatography is gaining widespread application in mutation detection for single nucleotide polymorphisms (SNP). The technique relies on temperature-modulated heteroduplex analysis (TMHA) by chromatographic separation of partially denatured DNA heteroduplexes from homoduplexes. Here, we demonstrate that fluorescent labeling is compatible with mutation analysis by this form of DNA chromatography and offers advantages over the use of unlabeled DNA fragments. Uniform labeling of wild-type and mutant alleles for TMHA yields peak patterns identical to unlabeled fragments. However, fluorescent labels increase retention times but do not influence resolution of heteroduplexes from homoduplexes. They increase sensitivity and decrease the amount of DNA required for analysis; e.g., in the case presented here, one allele can be detected in the presence of a 500-fold excess of another allele. Furthermore, allele-specific wild-type probes, fluorescently labeled on one strand only, make it possible to selectively monitor specific homoduplexes and wild-type/mutant heteroduplexes. This, in combination with an internal homoduplex standard, greatly reduces the complexity of fluorescence chromatograms compared with chromatograms recorded in the UV. These simplified chromatograms, in which only the internal homoduplex standard and the labeled heteroduplex are detected in the presence of a mutation, greatly facilitate the detection and identification of mutant alleles.

Base Sequence↗
PubMed2001

Extreme geographical fixation of variation in the Plasmodium falciparum gamete surface protein gene Pfs48/45 compared with microsatellite loci.

Comparing patterns of genetic variation at multiple loci in the genome of a species can potentially identify loci which are under selection. The large number of polymorphic microsatellites in the malaria parasite Plasmodium falciparum are available markers to screen for selectively important loci. The Pfs48/45 gene on Chromosome 13 encodes an antigenic protein located on the surface of parasite gametes, which is a candidate for a transmission blocking vaccine. Here, genotypic data from 255 P. falciparum isolates are presented, which show that alleles and haplotypes of five single nucleotide polymorphisms (SNPs) in the Pfs48/45 gene are exceptionally skewed in frequency among different P. falciparum populations, compared with alleles at 11 microsatellite loci sampled widely from the parasite genome. Fixation indices measuring inter-population variance in allele frequencies (F(ST)) were in the order of four to seven times higher for Pfs48/45 than for the microsatellites, whether considered (i) among populations within Africa, or (ii) among different continents. Differing mutational processes at microsatellite and SNP loci could generally affect the population structure at these different types of loci, to an unknown extent which deserves further investigation. The highly contrasting population structure may also suggest divergent selection on the amino acid sequence of Pfs48/45 in different populations, which plausibly indicates a role for the protein in determining gamete recognition and compatibility.

Africa↗
PubMed2004

A novel candidate region for ALS on chromosome 14q11.2.

Sequence variations with biologic effect in ALS have been identified in the gene for vascular endothelial growth factor (VEGF). The gene for a related protein, angiogenin, lies on chromosome 14q11.2. Analysis of the angiogenin (ANG) gene in the authors' population has demonstrated a significant allelic association with the rs11701 single nucleotide polymorphism (SNP) and identified a novel mutation in two individuals with sporadic ALS that potentially inhibits angiogenin function. These observations propose a candidate region for ALS on chromosome 14q11.2 and suggest that other genes with similar function to VEGF may be important in the pathogenesis of ALS.

Aged↗
PubMed2006

Paraoxonase cluster polymorphisms are associated with sporadic ALS.

BACKGROUND: Paraoxonases (PONs) are involved in the detoxification of organophosphate pesticides and chemical nerve agents. Due to a reported possible twofold increased risk of ALS in Gulf War veterans and the associations of PON1 polymorphisms with the neurologic symptom complex of the Gulf War syndrome, the authors investigated the association between sporadic ALS (SALS) and PON gene cluster variants in a large North American Caucasian family-based and case-control cohort (N = 1,891). METHODS: Clinically definite and probable ALS was diagnosed according to the revised El Escorial criteria, exclusion of family history of ALS, and SOD1 mutation analysis. Single nucleotide polymorphism (SNP) genotyping was done using TaqMan assays on ABI7900HT. Data were analyzed using SPSS, Haploview, FBAT, and THESIAS. RESULTS: A haploblock of high linkage disequilibrium (LD) spanning PON2 and PON3 was associated with SALS. The SNPs rs10487132 and rs11981433 were in strong LD and associated with SALS in the trio (parents-affected child triad) model. The association of rs10487132 was replicated in 450 nuclear pedigrees comprising trios and discordant sibpairs. No association was found in case-control models, and their haplostructure was different from that of the trios with overall reduced LD. Resequencing identified an intronic variant (rs17876088) that differentiated between detrimental and protective SALS haplotypes. CONCLUSION: This study demonstrates evidence of significant association of variants in the Paraoxonase gene cluster with sporadic ALS and is compatible with the hypothesis that environmental toxicity in a susceptible host may precipitate ALS.

Adult↗
PubMed2003

[The SNPs analysis of encoding sequence of interacting factor gene in Chinese population].

OBJECTIVE: To screen the variations of TG interacting factor(TGIF) gene in encoding sequence in Chinese high myopia patients and normal controls and to analyze the SNPs of TGIF gene encoding sequence in Chinese population. METHODS: Genomic DNA was collected from 204 probands with high myopia and 112 unrelated persons without high myopia. The coding sequences of TGIF gene in 316 subjects were analyzed by using exon-by-exon PCR heteroduplex-SSCP analysis and sequencing. RESULTS: There were 3 types of SNP and one single nucleotide mutation in the coding sequence of TGIF gene: IVS-2 nt350 G --> T(36/204), codon140 CCA --> CCG; Pro140Pro codon163 CCG --> CTG;Pro163Leu and codon126 GTG --> GCG; Val126Ala(1/204). The SNPs of codon140 CCA --> CCG and codon163 CCG --> CTG were composed of 3 alleles and 5 genotypes in Chinese population which abide by Hardy-Weinberg law. CONCLUSION: There was no evidence to prove that mutations in the TGIF gene are responsible for the high myopia in Chinese. Three SNPs of coding sequence TGIF gene in Chinese population abide by Hardy-Weinberg law.

China↗
PubMed2005

Linkage disequilibrium analysis identifies an FGFR1 haplotype-tag SNP associated with normal variation in craniofacial shape.

Mutations in FGFR1 and TWIST1 have been reported to affect the timing of calvarial suture fusion resulting in craniosynostosis and facial abnormalities. We screened nonpathologic populations for genetic polymorphisms that may associate with normal craniofacial variation. We identified 17 single-nucleotide polymorphisms (SNPs) in FGFR1, 6 of which were novel (g.8591855G-->A, g.8593685G-->A, g.8602303C-->T, g.8602475A-->G (p.Ile293Val), g.8605849C-->T, g.8607868G-->A). No SNPs were found in TWIST1. FGFR1 SNP haplotypes were reconstructed for Caucasian, Asian, Australian Aboriginal, and African American populations. All populations shared two linkage disequilibrium blocks, with one haplotype-tag SNP (htSNP) tagging each block. The htSNP g.8592931G-->C was found to have a significant negative correlation with the cephalic index for all populations (R = -0.187, p = 0.036), with larger correlations in Asians and females. This finding is a starting point in the identification of a set of SNPs that can be genotyped to determine both normal and disease craniofacial phenotypes.

Black or African American↗
PubMed2003

Haplotypic relationship between SNP and microsatellite markers at the NOS2A locus in two populations.

The density of genetic markers required for successful association mapping of complex diseases depends on linkage disequilibrium (LD) between non-functional markers and functional variants. The haplotypic relationship between stable markers and potentially unstable but highly informative markers (e.g. microsatellites) indicates that LD might be maintained over considerable genetic distance in non-African populations, supporting the use of such 'mixed marker haplotypes' in LD-based mapping, and allowing inferences to be drawn about human origins. We investigated sequence variation in the proximal 2.6 kb of the inducible nitric oxide synthase (NOS2A) promoter and the relationship between SNP haplotypes and a pentanucleotide microsatellite (the 'NOS2A(-2.6) microsatellite') in Gambians and UK Caucasians. UK Caucasians exhibited a subset of sequence diversity observed in Gambians, sharing four of 11 SNPs and a similar haplotypic structure. Five SNPs were found in the sequence of interspersed repetitive DNA elements. In both populations, there was dramatic loss of LD between SNP haplotypes and microsatellite alleles across a very short physical distance, suggesting a high intrinsic mutation rate of the NOS2A(-2.6) microsatellite, the SNP haplotypes are relatively ancient, or that this was a region of frequent recombination. Understanding locus- and population-specific LD is essential when designing and interpreting genetic association studies.

Gambia↗
PubMed2006

Diagnostic mutational analysis of MECP2 in Korean patients with Rett syndrome.

Rett syndrome (RTT) is an X-linked dominant neurodevelopmental disorder affecting 1 per 10,000-15,000 female births worldwide. The disease-causing gene has been identified as MECP2 (methyl-CpG-binding protein 2). In this study, we performed diagnostic mutational analysis of the MECP2 gene in RTT patients. Four exons and a putative promoter of the MECP2 gene were analyzed from the peripheral blood of 43 Korean patients with Rett syndrome by PCR-RFLP and direct sequencing. Mutations were detected in the MECP2 gene in approximately 60.5% of patients (26 cases/43 cases). The mutations consisted of 14 different types, including 9 missense mutations, 4 nonsense mutations and 1 frameshift mutation. Of these, three mutations (G161E, T311M, p385fsX409) were newly identified and were determined to be disease-causing mutations by PCR- RFLP and direct sequencing analysis. Most of the mutations were located within MBD (42.3%) and TRD (50%). T158M, R270X, and R306C mutations were identified at a high frequency. Additionally, an intronic SNP (IVS3+23C>G) was newly identified in three of the patients. IVS3+23C>G may be a disease-related and Korea-specific SNP for RTT. L100V and A201V are apparently disease-causing mutations in Korean RTT, contrary to previous studies. Disease-causing mutations and polymorphisms are important tools for diagnosing RTT in Koreans. The experimental procedures used in this study should be considered for clinical molecular biologic diagnosis.

Base Sequence↗
PubMed2005

Impact of SRC homology 2-containing inositol 5'-phosphatase 2 gene polymorphisms detected in a Japanese population on insulin signaling.

Src homology 2-containing 5'-inositol phosphatase 2 (SHIP2) is known to be one of lipid phosphatases converting PI(3,4,5)P3 to PI(3,4)P2 in the negative regulation of insulin signaling with the fundamental impact on the state of insulin resistance. To clarify the possible involvement of SHIP2 in the pathogenesis of human type 2 diabetes, we examined the relation of human SHIP2 gene polymorphisms to type 2 diabetes in a Japanese population. We identified 10 polymorphisms including four missense mutations. Among them, single nucleotide polymorphism (SNP)3 (L632I) was located in the 5'-phosphatase catalytic region, and SNP5 (N982S) was adjacent to the phosphotyrosine binding domain binding consensus motif in the C terminus. SNP3 was found more frequently in control subjects than in type 2 diabetic patients, suggesting that this mutation might protect from insulin resistance. Transfection study showed that expression of SNP3-SHIP2 inhibited insulin-induced PI(3,4,5)P3 production and Akt2 phosphorylation less potently than expression of wild-type SHIP2 in CHO-IR cells. Insulin-induced tyrosine phosphorylation of SNP5-SHIP2 was decreased compared with that of wild-type SHIP2, resulting in increased Shc/Grb2 association and MAPK activation. These results indicate that the polymorphisms of SHIP2 are implicated, at least in part, in type 2 diabetes, possibly by affecting the metabolic and/or mitogenic insulin signaling in the Japanese population.

Aged↗
PubMed2000

Microchip electrophoresis: a method for high-speed SNP detection.

As a trial practical application, we have applied optimized microfabricated electrophoresis devices, combined with enzymatic mutation detection methods, to the determination of single nucleotide polymorphism (SNP) sites in the p53 suppressor gene. Using clinical samples, we have achieved robust assays with quality factors as good as conventional electrophoresis in approximately 100 s. This is 10 and 50 times faster than capillary and slab gel electro-phoresis, respectively. The method was highly accurate with an average error of mutation site measurement of only +/-5 bp. No clean-up of the digestion mixtures was needed prior to injection. This greatly simplifies sample handling relative to capillary instruments, which is important for high-throughput screening applications. Following identification, absolute mutation determination of the screened samples was achieved in a second microdevice optimized for four-color DNA sequencing. Total run time was 25 min in this second device and sequencing data were in full agreement with ABI Prism 377 sequencing runs which required 3.5 h. The tandem application of microdevices for location then full characterization of SNPs appears to confirm many of the improvements claimed for future application of microdevices in practical scaled screening for mutational analysis.

DNA Mutational Analysis↗
PubMed2005

Single nucleotide polymorphisms in K(ATP) channels: muscular impact on type 2 diabetes.

ATP-sensitive K+ channels (K(ATP) channels) play an important role in glucose homeostasis. A single nucleotide polymorphism (SNP) in the Kir6.2 subunit causes a point mutation of Glu23 to lysine and reduces the ATP sensitivity of pancreatic K(ATP) channels. The SNP found in 58% of Caucasians accounts for 15% of type 2 diabetes. Here we show evidence for dysregulations of muscular K(ATP) channels with the E23K variation. We were particularly interested in the channel modulation by intracellular protons, as pH changes widely and frequently in skeletal muscles. Surprisingly, we found that the defect of the E23K variant was more related to pH than ATP. A level of intracellular acidification seen during exercise not only activated the E23K channel more readily than the wild type, but also relieved the channel inhibition by ATP, leading to a vast increase in the channel open-state probability by approximately sevenfold at pH 6.8 over the wild-type channel at pH 7.4. Considering the reduction in sarcolemmal excitability, muscle fatigue, and impairment of muscular glucose uptake found previously by genetically disrupting K(ATP) channels, it is likely that the E23K variant in muscular K(ATP) channels affects systemic glucose homeostasis and poses an important risk factor for type 2 diabetes and obesity.

Amino Acid Substitution↗