NOS1AP Research Articles

An Improved Clinical and Genetics-Based Prediction Model for Diabetic Foot Ulcer Healing.

Objective: The goal of this investigation was to use comprehensive prediction modeling tools and available genetic information to try to improve upon the performance of simple clinical models in predicting whether a diabetic foot ulcer (DFU) will heal. Approach: We utilized a cohort study (n = 206) that included clinical factors, measurements of circulating endothelial precursor cells (CEPCs), and fine sequencing of the NOS1AP gene. We derived and selected relevant predictive features from this patient-level information using statistical and machine learning techniques. We then developed prognostic models using machine learning approaches and assessed predictive performance. The presentation is consistent with TRIPOD requirements. Results: Models using baseline clinical and CEPC data had an area under the receiver operating characteristic curve (AUC) of 0.73 (0.66-0.80). Models using only single nucleotide polymorphisms (SNPs) of the NOS1AP gene had an AUC of 0.67 (95% confidence interval, CI: [0.59-0.75]). However, models incorporating baseline and SNP information resulted in improved AUC (0.80, 95% CI [0.73-0.87]). Innovation: We provide a rigorous analysis demonstrating the predictive potential of genetic information in DFU healing. In this process, we present a framework for using advanced statistical and bioinformatics techniques for creating superior prognostic models and identify potentially predictive SNPs for future research. Conclusion: We have developed a new benchmark for which future predictive models can be compared against. Such models will enable wound care experts to more accurately predict whether a patient will heal and aid clinical trialists in designing studies to evaluate therapies for subjects likely or unlikely to heal.

The role of the neural NO synthase adapter protein in the pathogenesis of metabolic syndrome and type 2 diabetes mellitus

The pathogenesis of metabolic syndrome (MS) is characterized by obesity, hypertension, dyslipidemia and insulin resistance. MS increases the risk of developing type 2 diabetes mellitus (DM2). The neuronal isoform of nitric oxide synthase (nNOS) is defined by complex protein-protein interactions, since nNOS, unlike other isoforms of NOS,contains a C-terminal PDZ domain, which allows it to conjugate with other proteins and, first of all, to interact with an adapter of neuronal, or type 1, nitric oxide synthase (NOS1AP), also denoted CAPON in our work. Changes in the interaction between nNOS and NOS1AP lead to metabolic disorders in brain, heart, liver and skeletal muscles, which plays a key role in the development of MS and T2DM. NOS1AP, interacting with the PDZ domain of nNOS, competes with the postsynaptic density protein (PSD95) and regulates the stability of subcellular localization of nNOS and enzyme expression during synapse formation. NOS1AP promotes nNOS binding to targets such as small GTPase (Dexras1), synapsines, regulating the formation of dendritic roots, mediates activation of the nNOS-p38MAP kinase pathway during excitotoxicity. It has been shown that single-nucleotide polymorphism of the NOS1AP gene and its overexpression in the myocardium leads to the manifestation of long QT syndrome, which is most clearly manifested in elderly patients with DM2. It was found that the genetic polymorphism of NOS1AP affects insulin secretion when using calcium blockers, and can promote the development of DM2. The functional role of NOS1AP in stabilizing the functions of skeletal muscle nNOS in the cytoskeletal complex associated with dystrophin/utrophin was discovered. The purpose of the review is to provide updated information on the role of NOS1AP and the nNOS/NOS1AP complex in the pathogenesis of MS and DM2. The potential molecular mechanisms of the interaction of NOS1AP with nNOS and with other proteins, which leads to change in nNOS activity, localization and content, are discussed.

Cardiac muscle-restricted partial loss of Nos1ap expression has limited but significant impact on electrocardiographic features.

Genome-wide association studies have identified sequence polymorphisms in a functional enhancer of the NOS1AP gene as the most common genetic regulator of QT interval and human cardiac NOS1AP gene expression in the general population. Functional studies based on in vitro overexpression in murine cardiomyocytes and ex vivo knockdown in zebrafish embryonic hearts, by us and others, have also demonstrated that NOS1AP expression levels can alter cellular electrophysiology. Here, to explore the role of NOS1AP in cardiac electrophysiology at an organismal level, we generated and characterized constitutive and heart muscle-restricted Nos1ap knockout mice to assess whether NOS1AP disruption alters the QT interval in vivo. Constitutive loss of Nos1ap led to genetic background-dependent variable lethality at or right before birth. Heart muscle-restricted Nos1ap knockout, generated using cardiac-specific alpha-myosin heavy chain promoter-driven tamoxifen-inducible Cre, resulted in tissue-level Nos1ap expression reduced by half. This partial loss of expression had no detectable effect on the QT interval or other electrocardiographic and echocardiographic parameters, except for a small but significant reduction in the QRS interval. Given that challenges associated with defining the end of the T wave on murine electrocardiogram can limit identification of subtle effects on the QT interval and that common noncoding NOS1AP variants are also associated with the QRS interval, our findings support the role of NOS1AP in regulation of the cardiac electrical cycle.

The influence of NOS1AP gene polymorphisms and childhood abuse on antisocial personality disorder in Chinese male violent inmates.

Antisocial personality disorder (ASPD) is a common behavioral pattern that causes sufferers to ignore or violate the rights of others. Though its cause is still unclear, previous studies have shown that childhood maltreatment is closely related to ASPD. The NOS1AP gene is associated with various neuropsychiatric diseases, but a linkage between it and ASPD has not yet been discovered. This study recruited ASPD and non-ASPD male subjects who had committed violent crimes from a prison in Nanjing, China. By comparing the two groups' genotypes, allele frequencies, and histories of childhood abuse, we explored the interaction between the NOS1AP gene and childhood maltreatment on the pathogenesis of ASPD. The results showed that polymorphism rs945713 in the NOS1AP gene was associated with ASPD and furthermore that this SNP may be involved in regulating the effect of childhood abuse on ASPD. This study found that childhood trauma increases the risk of ASPD in violent adult male inmates; for prisoners with ASPD, it is critical to pay attention to their childhood trauma and take early psychological intervention.

NOS1AP Interacts with α-Synuclein and Aggregates in Yeast and Mammalian Cells.

The NOS1AP gene encodes a cytosolic protein that binds to the signaling cascade component neuronal nitric oxide synthase (nNOS). It is associated with many different disorders, such as schizophrenia, post-traumatic stress disorder, autism, cardiovascular disorders, and breast cancer. The NOS1AP (also known as CAPON) protein mediates signaling within a complex which includes the NMDA receptor, PSD-95, and nNOS. This adapter protein is involved in neuronal nitric oxide (NO) synthesis regulation via its association with nNOS (NOS1). Our bioinformatics analysis revealed NOS1AP as an aggregation-prone protein, interacting with α-synuclein. Further investigation showed that NOS1AP forms detergent-resistant non-amyloid aggregates when overproduced. Overexpression of NOS1AP was found in rat models for nervous system injury as well as in schizophrenia patients. Thus, we can assume for the first time that the molecular mechanisms underlying these disorders include misfolding and aggregation of NOS1AP. We show that NOS1AP interacts with α-synuclein, allowing us to suggest that this protein may be implicated in the development of synucleinopathies and that its aggregation may explain the relationship between Parkinson’s disease and schizophrenia.

Association of single nucleotide polymorphic variants of the <i>NOS1AP</i> gene with QT interval duration

Highlights. The association of single nucleotide polymorphic variants rs12143842 and rs4657139 of the NOS1AP gene with the duration of the QT interval was found in men of the Siberian population.Aim. To study the association of single nucleotide variants rs12143842 and rs4657139 of the NOS1AP gene with the duration of the QT interval.Methods. The study sample of men (1353 people) aged 25–69 years was formed from the DNA bank of participants in the international HAPIEE project and screening of young people 25–44 years old, residents of Novosibirsk. From each age subgroup (25–29, 30–34, …, 65–69 years old), about 10–15% of men with the shortest, average and longest QT interval were selected and the corresponding groups were formed. Genotyping of rs4657139 was carried out using PCR with RFLP (polymerase chain reaction followed by restriction fragment length polymorphism analysis). Genotyping rs12143842 – using RT-PCR (real-time polymerase chain reaction).Results. At the age of over 50 years, the CC genotype rs12143842 was detected in 66.1% of men in the group with a short and average QT interval and in 50.6% in the group with a long QT interval, while the TT genotype prevailed in the group with a long QT interval, 10, 8% of cases (odds ratio (OR) = 3.345, 95% confidence interval (CI) 1.149–9.739, p = 0.02). The homozygous TT genotype rs4657139 was more common in the long QT group, in 20.1% of cases, while the AA and AT genotypes predominated in the short, average QT groups (p = 0.041). A similar trend persists when separating by age in people over 50 years of age (p = 0.031) and when comparing genotype frequencies in the long and average QT groups in the model TT vs AA + AT & long QT vs short + average QT (p = 0.003).Conclusion. Single nucleotide variants rs12143842 and rs4657139 of the NOS1AP gene are associated with the duration of the QT interval in male residents of Novosibirsk.

GENETICS OF PARANOIDPERSONALITYDISORDER

Paranoid personality disorder (PPD) is characterized by the following leading features: excessive sensitivity to failures and refusals; inclination to persistently endure even minor insults and injuries or slights, refusing to forgive them; suspicion and distortion of facts, interpretation of friendly or neutral actions of other people as hostile or contemptuous; unjustified suspicions of sexual infidelity of a partner; unfounded concern about the imaginary conspiracy of events both in relation to himself and around the world; feeling of one's own usually exaggerated significance; unfounded militant defense of their personal rights. The prevalence of PPD is 2.3-4.4% and is more often diagnosed in men. Heritability of PPD varies from 28% to 66%.
 By now various authors have described 16 genes associated with the development of PPD: SLC6A4, COMT, CACNA1C, NOS1AP, DYNC1I1 and 11 genes of mitochondrial complex 1. The SLC6A4 gene (17q11.2) encodes a reverse serotonin transporter. A slight deletion in the promoter of this gene reduces its activity and can minimize the expression of paranoid traits. The product of the COMT gene (22q11.21) is actively involved in dopamine metabolism. A G-to-A transition atcodon 158 of this gene increases its activity by 3-4 times and, as a consequence, decreases dopamine expression in the prefrontal cortex, which causes paranoid symptoms of personality disorders. The CACNA1C gene (12p13.33) encodes a protein that plays an important role in the formation and activity of brain neurons. The single nucleotide polymorphism rs1006737, located in the 3rd intron of this gene, is associated with PPD, schizophrenia, schizotypal personality disorder, major depressive disorder and bipolar disorder.
 Mitochondrial complex 1 and cellular bioenergetic pathways play a significant role in the etiology and features of PPD and schizophrenia. Significant changes in expression of 11 genes were detected in patients with PPD compared to the control sample. Expression of genes NDUFS1 (2q33.3), NDUFV1 (11q13.2), NDUFV2 (18p11.22), NDUFB5 (3q26.33), NDUFB9 (8q24.13), NDUFA13(19p13.11), NDUFA8 (9q33. 2) and NDUFA5 (7q31.32) was increased, and the genes NDUFB11 (Xp11.3), NDUFS7 (19p13.3) and NDUFS8 (11q13.2) were decreased. The NDUFS1 gene expression was particularly high. None of the sevenmitochondrial genes showed a change in expression,which may reduce the importance of a maternal patternin the heritance of PPD.The results of the study showed that the NDUFS1 gene may be a specific marker for PPD.
 In the presence of relevant genetic factors certain environmental conditions can provoke the development of PPD. It is possible to predict PPD on the presence of NOS1AP (1q23.3) gene polymorphisms and childhood abuse. The protein encoded by this gene is involved in the functioning of brain synapses. There is shown that emotional violence and SNPs rs348624 and rs4145621, located respectively in the 9th exon and 3rd intron of the NOS1AP gene, reliably predict PPD.
 In addition to described above 16 genes, whose variants are reliably involved in PPD, various researchers have identified at least 8 other genes that are likely to be associated with PPD, although they have been identified in the study of other mental disorders, mainly schizophrenia.
 A review of available scientific sources on PPD genetics shows that research of this problem isin its beginning. It is necessary to expand and deepen these studies on the basis of the most modern molecular genetic technologies, one of which is the genome-wide associations study. This technology makes it possible not only to detect candidate genes, but also to determine the nature of mutations that cause hereditary disease. Such mutations can be single nucleotide polymorphisms, small insertions / deletions and changes in the number of copies. In addition, they can be located not only within genes (in exons and introns), but also in intergenic regions of DNA. Gene expression can be affected not only by mutations within its exons, but also by mutations within its introns and intergenic DNA regions.

Роль некоторых генетических полиморфизмов в развитии внезапной сердечной смерти в Забайкальском крае

Aim of the study. To study genetic polymorphisms rs10798 KCNQ1, rs3010396 CASQ2, rs20455 KIF6, rs2298566 SNX19, rs12143842 NOS1AP of subjects who died due to sudden cardiac death in Trans-Baikal Territory. Material and Methods. Over the period of 2017-2020, a total of 2211 autopsy protocols of subjects who died due to SCD were analysed. Th ese patient constituted the 1st study group (n=113). The control group consisted of healthy volunteers (n=70). The groups were comparable in age and gender. Molecular and genetic typing of the studied genes was performed. Results. The CC genotype of the single-nucleotide polymorphism rs3010396 CASQ2 showed statistical signifi cance in comparison with the control group(the chi-squared=26.95, df=2, p=0.001). The TT genotype was predominant in the control group amounting to 60% against 19.5% in the study group. Single-nucleotide polymorphism rs2298566 of gene SNX19 was also observed to be of statistical significance in the group of subjects who died from myocardial infarction. In the group of patients with SCD, rs20455 KIF6 and rs12143842 NOS1AP were of signifi cance along with rs3010396 CASQ2. Conclusion. Single-nucleotide polymorphism rs3010396 of the CASQ2 gene can be a predictor of sudden cardiac death, since in the 1st study group with this genotype showed its statistical signifi cance in all nosological groups. However, in the group, in which sudden cardiac death (cases coded I46.1 according to ICD-10) was indicated as the fi nal diagnosis, in addition to their statistical signifi cance single-nucleotide polymorphisms of the gene KIF6 rs20455, rs12143842 NOS1AP gene were noted; in the group where the cause of death was myocardial infarction, rs2298566 SNX19 gene polymorphism had statistical signifi cance. The results obtained make it possible to consider these polymorphisms as possible predictors of sudden cardiac death in the population of the Trans-Baikal Territory.

NOS1AP SNPs related to sudden arrhythmic death syndrome

Between 12–20 % of all Sudden Cardiac Death (SDC) occurs in individuals without previous symptoms of cardiac disease, which is known as Sudden Arrhythmic Death Syndrome (SADS). Recent studies identified the NOS1AP gene as new genetic marker to increase the risk of SDC. Here, we analyzed five SNPs of the NOS1AP gene by PCR-HRM in order to evaluate its ability as diagnostic and predictive biomarkers of the SADS.

Hepatic nitric oxide synthase 1 adaptor protein regulates glucose homeostasis and hepatic insulin sensitivity in obese mice depending on its PDZ binding domain.

BackgroundNOS1AP is an adaptor protein and its SNP rs12742393 was associated with type 2 diabetes (T2D). However, it remains uncertain whether NOS1AP plays a role in regulation of insulin sensitivity. Hepatic insulin resistance contributed to the development of T2D. Here, our investigation was focused on whether NOS1AP is involved in the regulation of hepatic insulin sensitivity and its underlying mechanisms.MethodsLiver specific NOS1AP condition knockout (CKO) and NOS1AP overexpression mice were generated and given a high fat diet. SNPs of NOS1AP gene were genotyped in 86 human subjects.FindingsNOS1AP protein is expressed in human and mouse liver. CKO mice exhibited impaired pyruvate, glucose and insulin tolerance, and increased lipid deposits in the liver. Conversely, NOS1AP overexpression in livers of obese mice improved pyruvate and/or glucose, and insulin tolerance, and attenuated liver lipid accumulation. Moreover, hepatocytes from CKO mice exhibited an elevated glucose production and mRNA expressions of Pc and Pck1. Overexpression of NOS1AP potentiated insulin-stimulated activation of IR/Akt in livers from obese mice. The insulin sensitizing effect of NOS1AP could be mimicked by overexpression of C-terminal domain of NOS1AP in ob/ob mice. Furthermore, NOS1AP overexpression in liver significantly inhibited p38 MAPK phosphorylation, and maintained ER homeostasis through p-eIF2a-ATF4-CHOP pathway. Subjects with rsl2742393 of NOS1AP have higher risk to develop hepatic steatosis.InterpretationOur data demonstrate a novel role of NOS1AP in regulating hepatic insulin sensitivity and p38 MAPK inactivation in obese mice, which makes NOS1AP a potential therapeutic target for the prevention and treatment of T2D.FundThis work was supported by the National Natural Science Foundation of China (81670707, 31340072) (to C. Wang), and National Basic Research Program of China (Nation 973 Program) (2011CB504001) (to W. Jia).

Generation of two human induced pluripotent stem cell (hiPSC) lines from a long QT syndrome South African founder population

We generated PSMi001-A and PSMi008-A hiPSC lines from two individuals belonging to a South African (SA) founder population in which the malignant KCNQ1-A341V mutation cosegregates with the Long QT Syndrome (LQTS) phenotype. PSMi001-A was derived from an asymptomatic KCNQ1-A341V mutation carrier, whereas PSMi008-A was derived from a healthy non-mutation carrier, heterozygous for the minor variant rs16847548 on the NOS1AP gene, associated with QT prolongation in the general population, and with a greater risk for cardiac arrest in the affected members of the SA founder population. The hiPSCs, generated using the Yamanaka's retroviruses, display pluripotent stem cell features and trilineage differentiation potential.

Hepatic Nitric Oxide Synthase 1 Adaptor Protein Regulates Glucose Homeostasis and Hepatic Insulin Sensitivity in Obese Mice Depending on Its PDZ Binding Domain

Background: NOS1AP is an adaptor protein and its SNP rs12742393 was associated with type 2 diabetes (T2D). However, it remains uncertain whether NOS1AP plays a role in regulation of insulin sensitivity. Hepatic insulin resistance contributed to the development of T2D. Here, we investigated whether NOS1AP is involved in the regulation of hepatic insulin sensitivity and its underlying mechanisms. Methods: Liver specific NOS1AP condition knockout (CKO) and NOS1AP overexpression mice were generated and fed with a high fat diet. SNPs of NOS1AP gene were genotyped in 86 human subjects. Findings: NOS1AP protein is highly expressed in human and mouse liver. CKO mice exhibited impaired pyruvate, glucose and insulin tolerance, and increased lipid deposits in the liver. Conversely, overexpression of NOS1AP in liver of obese mice improved pyruvate and/or glucose, and insulin tolerance, and attenuated liver lipid accumulation. Moreover, hepatocytes from CKO mice exhibited an elevated glucose production and mRNA expressions of Pc and Pck1. Overexpression of NOS1AP potentiated insulin-stimulated activation of IR/Akt in liver from obese mice. The insulin sensitizing effect of NOS1AP could be mimicked by overexpression of C-terminal domain of NOS1AP in ob/ob mice. Furthermore, NOS1AP expression in liver was associated with ER homeostasis through down-regulation of p-eIF2a-ATF4-CHOP pathway. Subjects with rsl2742393 of NOS1AP have a higher risk for hepatic steatosis. Interpretation: Our data demonstrate a novel role of NOS1AP in regulating hepatic insulin sensitivity and maintenance of ER homeostasis in liver, which implicates NOS1AP a therapeutic target for the prevention and treatment of T2D. Funding Statement: This work was supported by the National Natural Science Foundation of China (81670707, 31340072) (to C. Wang), and National Basic Research Program of China (Nation 973 Program) (2011CB504001) (to W. Jia). Declaration of Interests: The authors declare no conflict of interests. Ethics Approval Statement: The protocol was approved by the Ethics Committee of the Shanghai Jiao Tong University Affiliated Sixth People’s Hospital (2018-KY-026 (K)) and followed the principles of the Declaration of Helsinki.

Generation of the human induced pluripotent stem cell (hiPSC) line PSMi007-A from a Long QT Syndrome type 1 patient carrier of two common variants in the NOS1AP gene

We generated human induced pluripotent stem cells (hiPSCs) from a symptomatic Long QT Syndrome (LQTS) type 1 patient, belonging to a South African (SA) founder population segregating the heterozygous mutation c.1022C > T p.A341V on the KCNQ1 gene. The patient is also homozygous for the two minor variants rs4657139 and rs16847548 on the NOS1AP gene, associated with greater risk for cardiac arrest and sudden death in LQTS mutation carriers of the founder population. hiPSCs, obtained using four retroviruses encoding the reprogramming factors OCT4, SOX2, cMYC and KLF4, display pluripotent stem cell characteristics, and can be differentiated into spontaneously beating cardiomyocytes (hiPSC-CMs).

Corrected QT Interval Prolongation in Psychopharmacological Treatment and Its Modulation by Genetic Variation

Several antipsychotics and antidepressants have been associated with electrocardiogram alterations, the most clinically relevant of which is the heart rate-corrected QT interval (QT_c) prolongation, a risk factor for sudden cardiac death. Genetic variants influence drug-induced QT_c prolongation and can provide valuable information for precision medicine. The effect of genetic variants on QT_c prolongation as well as the possible interaction between polymorphisms and risk medications in determining QT_c prolongation were investigated. Medications were classified according to their known risk of inducing QT_c prolongation (high-to-moderate, low, and no risk). QT_c duration and risk of QT_c > median value were investigated in a sample of 77 patients with mood or psychotic disorders being treated with antidepressants and antipsychotics, and who had at least 1 ECG recording. A secondary analysis considered QT_c percentage change in patients (n = 25) with 2 ECG recordings. Single-nucleotide polymorphisms previously associated with QT_c prolongation during treatment with psychotropic medications were investigated. No association survived after multiple-testing correction. The best results for modulation of QT_c duration were identified for rs10808071 (the ABCB1 gene, nominal p = 0.007) when at least 1 medication with a moderate-to-high risk was prescribed, and for rs12029454 (the NOS1AP gene) in patients taking at least 1 medication with a cardiovascular risk (nominal p = 0.008). In the secondary analysis, rs2072413 (the KCNH2 gene) was the top finding for the modulation of QT_c percentage change (nominal p = 0.001) when 1 drug with a moderate-to-high risk was added compared to baseline. Despite the limited power of this study, our results suggest that ABCB1, NOS1AP, and KCNH2 may play a role in QT_c duration/prolongation during treatment with psychotropic drugs.

Histological Study of the Effect of Semicarbazide on Testicular Seminiferous Tubules of Juvenile Albino Rat

To investigate the single nucleotide polymorphism of NOS1AP gene with sudden unexpected death (SUD) during daily activities. The heart blood samples were collected from 60 SUD cases in normal daily activities as SUD group and the peripheral blood samples from 80 random unrelated cases as control group. The genome DNAs from all cases were isolated and the gene sequences were analyzed from specific primers of some SNP (rs10494366, rs10918859, rs12143842, rs12742393, rs3751284, and rs348624) of NOS1AP. The allele frequency and genotype frequency were calculated and the difference in these SNP between SUD group and control group were analyzed. The allele frequency and genotype frequency of rs3751284 which located at the sixth exon domain had significant statistical differences between the two groups (P<0.05). The minor allele frequency of rs3751284 was 0.325 in SUD group and was 0.475 in control group. rs3751284 might be a susceptibility locus for SUD.

Sex is a moderator of the association between NOS1AP sequence variants and QTc in two long QT syndrome founder populations: a pedigree-based measured genotype association analysis

BackgroundSequence variants in the NOS1AP gene have repeatedly been reported to influence QTc, albeit with moderate effect sizes. In the long QT syndrome (LQTS), this may contribute to the substantial QTc variance seen among carriers of identical pathogenic sequence variants. Here we assess three non-coding NOS1AP sequence variants, chosen for their previously reported strong association with QTc in normal and LQTS populations, for association with QTc in two Swedish LQT1 founder populations.MethodsThis study included 312 individuals (58% females) from two LQT1 founder populations, whereof 227 genotype positive segregating either Y111C (n = 148) or R518* (n = 79) pathogenic sequence variants in the KCNQ1 gene, and 85 genotype negatives. All were genotyped for NOS1AP sequence variants rs12143842, rs16847548 and rs4657139, and tested for association with QTc length (effect size presented as mean difference between derived and wildtype, in ms), using a pedigree-based measured genotype association analysis. Mean QTc was obtained by repeated manual measurement (preferably in lead II) by one observer using coded 50 mm/s standard 12-lead ECGs.ResultsA substantial variance in mean QTc was seen in genotype positives 476 ± 36 ms (Y111C 483 ± 34 ms; R518* 462 ± 34 ms) and genotype negatives 433 ± 24 ms. Female sex was significantly associated with QTc prolongation in all genotype groups (p < 0.001). In a multivariable analysis including the entire study population and adjusted for KCNQ1 genotype, sex and age, NOS1AP sequence variants rs12143842 and rs16847548 (but not rs4657139) were significantly associated with QT prolongation, +18 ms (p = 0.0007) and +17 ms (p = 0.006), respectively. Significant sex-interactions were detected for both sequent variants (interaction term r = 0.892, p < 0.001 and r = 0.944, p < 0.001, respectively). Notably, across the genotype groups, when stratified by sex neither rs12143842 nor rs16847548 were significantly associated with QTc in females (both p = 0.16) while in males, a prolongation of +19 ms and +8 ms (p = 0.002 and p = 0.02) was seen in multivariable analysis, explaining up to 23% of QTc variance in all males.ConclusionsSex was identified as a moderator of the association between NOS1AP sequence variants and QTc in two LQT1 founder populations. This finding may contribute to QTc sex differences and affect the usefulness of NOS1AP as a marker for clinical risk stratification in LQTS.

WHOLE GENOME SEQUENCE ANALYSIS OF FAMILIAL LATE-ONSET ALZHEIMER’S DISEASE

As part of the national Alzheimer’s Disease Sequencing Project (ADSP), genome-wide linkage analysis was performed in 111 multi-ethnic families multiply affected by Late Onset Alzheimer’s Disease (LOAD), with admixture mapping also carried out on Hispanic pedigrees. WGS data were generated for 578 subjects (affected and unaffected members) from 111 families (67 Caribbean-Hispanic [CH], 44 non-Hispanic White [NHW]) and 30 multigenerational Dutch families (DF). Based on linkage support from multiple CH families, genomic regions on 7p14, 11q12, and 3q29 (based on one CH family), were prioritized for WGS analysis; regions on 1q23, 14q32, and regions on chr1, 4-6, 10, 16 and 18 (because of strong results in single families) were prioritized in the set of NHW families. In DF, AD is linked to chromosome 5p14.3. Results from admixture mapping prioritized a region on chr13 in the CH families. Prioritization of the sequence variants was performed using multiple criteria including: segregation with disease, allele frequency, functional annotation, and other datasets such as the ADSP case-control dataset. Four missense variants under 7q14 and 5 variants under 11q12 segregate in at least 1 CH family, including GHRHR and TMEM132A. We identified several intronic variants in the 3q29 region segregating with LOAD in multiple CH families. Further annotation of the non-coding variants suggests regulatory features. Analysis of the NHW families has identified 19 genic and 11 intergenic variants of high priority. Three of these are NOS1AP gene variants; the variants segregated with disease (including one with CADD score of 13.6), were absent from unaffecteds, and NOS1AP showed nominal disease association in the ADSP case-control dataset (p=0.049). Additional intergenic variants segregated with disease and likely influence transcription factor binding (CATO annotation). Within the 15q14.3 region, 2 deleterious variants (PRDM9 and Drosha) and 5 intergenic variants with a CADD score>15 were found to be shared in by all relatives of the major DF. Additional analysis is ongoing. These results suggest that both coding and non-coding rare variants influence LOAD susceptibility, and show the continued utility of family-based approaches. Variants identified are currently being validated using orthogonal technologies, and follow-up analyses are being conducted.

NOS1AP Polymorphisms Modify QTc Interval Duration But Not Cardiac Arrest Risk in Hypertrophic Cardiomyopathy.

The accurate prediction of the risk of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) remains elusive. Corrected QT interval (QTc) duration is a known risk factor in various cardiac conditions. Single nucleotide polymorphisms (SNPs) have been linked to QTc length, and to SCD. Here we investigated the role of 21 candidate SNPs in QTc duration and SCD events in patients with HCM. This HCM registry-based study included patients with an ECG, medical history, first SCD event data, and DNA available. Each individual SNP was assessed using logistic regression for associations with 2 outcomes: a prolonged QTc ( ≥440 milliseconds), and first SCD event (SCD, resuscitated cardiac arrest, and appropriate implantable cardioverter defibrillator (ICD) shock for ventricular fibrillation/ventricular tachycardia (VF/VT). In 272 HCM patients, there were 31 SCD events (8 SCD, 9 resuscitated cardiac arrest, 14 ICD shocks for VF/VT; 11%). A QTc ≥ 500 milliseconds was associated with SCD events on multivariate analysis (odds ratio [OR] = 4.0, 95% confidence interval [CI], 1.19-12.02, P = 0.016). In 228 Caucasian patients, 2 SNPs in the NOS1AP gene (rs10494366 and rs12143842) were associated with a prolonged QTc after correction for multiple testing. This remained significant after adjustment for current age, sex, and ≥1 SCD risk factor (OR 1.59 per copy of the minor allele, 95% CI 1.08-2.39, P = 0.022, and OR 1.63, 95% CI 1.09-2.49, P = 0.020, respectively). No SNPs were directly associated with SCD events. SNPs in the NOS1AP gene influence QTc interval duration but we have not demonstrated a direct association with the risk of SCD.

Genetic markers of repolarization and arrhythmic events after acute coronary syndromes

There is a genetic contribution to the risk of ventricular arrhythmias in survivors of acute coronary syndromes (ACS). We wished to explore the role of 33 candidate single nucleotide polymorphisms (SNPs) in prolonged repolarization and sudden death in patients surviving ACS. A total of 2,139 patients (1680 white ethnicity) surviving an admission for ACS were enrolled in the prospective Coronary Disease Cohort Study. Extensive clinical, echocardiographic, and neurohormonal data were collected for 12 months, and clinical events were recorded for a median of 5 years. Each SNP was assessed for association with sudden cardiac death (SCD)/cardiac arrest (CA) and prolonged repolarization at 3 time-points: index admission, 1 month, and 12 months postdischarge. One hundred six SCD/CA events occurred during follow-up (6.3%). Three SNPs from 3 genes (rs17779747 [KCNJ2], rs876188 [C14orf64], rs3864180 [GPC5]) were significantly associated with SCD/CA in multivariable models (after correction for multiple testing); the minor allele of rs17779747 with a decreased risk (hazard ratio [HR] 0.68 per copy of the minor allele, 95% CI 0.50-0.92, P = .012), and rs876188 and rs386418 with an increased risk (HR 1.52 [95% CI 1.10-2.09, P = .011] and HR 1.34 [95% CI 1.04-1.82, P = .023], respectively). At 12 months postdischarge, rs10494366 and rs12143842 (NOS1AP) were significant predictors of prolonged repolarization (HR 1.32 [95% CI 1.04-1.67, P = .022] and HR 1.30 [95% CI 1.01-1.66, P = .038], respectively), but not at earlier time-points. Three SNPs were associated with SCD/CA. Repolarization time was associated with variation in the NOS1AP gene. This study demonstrates a possible role for SNPs in risk stratification for arrhythmic events after ACS.

Association of common variants in NOS1AP gene with sudden unexplained nocturnal death syndrome in the southern Chinese Han population

Here, we investigate the association of common polymorphisms of the NOS1AP gene with sudden unexplained nocturnal death syndrome (SUNDS) in the southern Chinese Han population. We genetically screened five common NOS1AP polymorphisms (rs10918594, rs12143842, rs16847548, rs12567209, and rs10494366) previously reported to be associated with QT interval variation and sudden cardiac death (SCD) in 123 sporadic SUNDS cases and 166 healthy controls using polymerase chain reaction (PCR) and direct DNA sequencing. In the present study, the A allele of rs12567209 was more common in controls than in SUNDS cases, which was associated with 0.656-fold decreased risk of SUNDS (95% confidence interval 0.431 to 0.998, P = 0.048) compared with G allele. Under the dominant genetic model, GA + AA genotype of rs12567209 was also more common in controls than in SUNDS cases, which was associated with 0.604-fold decreased risk of SUNDS (95 % confidence interval 0.368 to 0.991, P = 0.045) compared with GG genotype. No significant associations of rs10918594, rs12143842, rs16847548, and rs10494366 with SUNDS were observed (P > 0.05). In haplotype analyses, the distribution of haplotype GCTA was significantly overrepresented in controls compared to SUNDS cases (P = 0.040). This is the first report of the association of common NOS1AP polymorphisms with SUNDS in the southern Chinese Han population. These findings suggest that the A allele of rs12567209 and haplotype GCTA may serve as a protective modifier.