Autosomal Dominant Model Research Articles

A de novo ARIH2 gene mutation was detected in a patient with autism spectrum disorders and intellectual disability

E3 ubiquitin protein ligase encoded by ARIH2 gene catalyses the ubiquitination of target proteins and plays a crucial role in posttranslational modifications across various cellular processes. As prior documented, mutations in genes involved in the ubiquitination process are often associated with autism spectrum disorder (ASD) and/or intellectual disability (ID). In the current study, a de novo heterozygous mutation was identified in the splicing intronic region adjacent to the last exon of the ARIH2 gene using whole exome sequencing (WES). We hypothesize that this mutation, found in an ASD/ID patient, disrupts the protein Ariadne domain which is involved in the autoinhibition of ARIH2 enzyme. Predictive analyses elucidated the implications of the novel mutation in the splicing process and confirmed its autosomal dominant inheritance model. Nevertheless, we cannot exclude the possibility that other genetic factors, undetectable by WES, such as mutations in non-coding regions and polygenic risk in inter-allelic complementation, may contribute to the patient's phenotype. This work aims to suggest potential relationship between the detected mutation in ARIH2 gene and both ASD and ID, even though functional studies combined with new sequencing approaches will be necessary to validate this hypothesis.

Rhodopsin mislocalization drives ciliary dysregulation in a novel autosomal dominant retinitis pigmentosa knock-in mouse model.

Rhodopsin mislocalization encompasses various blind conditions. Rhodopsin mislocalization is the primary factor leading to rod photoreceptor dysfunction and degeneration in autosomal dominant retinitis pigmentosa (adRP) caused by class I mutations. In this study, we report a new knock-in mouse model that harbors a class I Q344X mutation in the endogenous rhodopsin gene, which causes rod photoreceptor degeneration in an autosomal dominant pattern. In RhoQ344X/+ mice, mRNA transcripts from the wild-type (Rho) and RhoQ344X mutant rhodopsin alleles are expressed at equal levels. However, the amount of RHOQ344X mutant protein is 2.7 times lower than that of wild-type rhodopsin, a finding consistent with the rapid degradation of the mutant protein. Immunofluorescence microscopy indicates that RHOQ344X is mislocalized to the inner segment and outer nuclear layers of rod photoreceptors in both RhoQ344X/+ and RhoQ344X/Q344X mice, confirming the essential role of the C-terminal VxPx motif in promoting OS delivery of rhodopsin. The mislocalization of RHOQ344X is associated with the concurrent mislocalization of wild-type rhodopsin in RhoQ344X/+ mice. To understand the global changes in proteostasis, we conducted quantitative proteomics analysis and found attenuated expression of rod-specific OS membrane proteins accompanying reduced expression of ciliopathy causative gene products, including constituents of BBSome and axonemal dynein subunit. Those studies unveil a novel negative feedback regulation involving ciliopathy-associated proteins. In this process, a defect in the trafficking signal leads to a reduced quantity of the trafficking apparatus, culminating in a widespread reduction in the transport of ciliary proteins.

Genetic Variants Associated with High Plasma Levels of Factor VIII and Von Willebrand Factor in a Family with Thrombotic Episodes

Background: High levels of factor VIII (FVIII) and von Willebrand factor (vWF) have been indicated as independent risk factors for venous thromboembolism. However, the genetic factors responsible for their increase remain still poorly known. In a woman referred to our Thrombosis unit following a venous thrombotic event, very high levels of FVIII and vWF were found at the acute episode and in subsequent measurements. High levels of FVIII and vWF were also detected in other family members, suggesting a possible genetic cause (Figure 1). Aim: To identify variants/genes associated with high levels of FVIII and vWF. Methods: In a large Italian family with high levels of FVIII/vWF and thrombotic episodes, whole-exome sequencing was performed in 12 family members (SureSelect-Agilent). Data were analyzed according to the guidelines of the Broad Institute (https://software.broadinstitute.org/gatk/best-practices/). Variants were annotated (Annovar) and filtered (KGGseq) according to an autosomal dominant inheritance model of high levels of FVIII or vWF. RNA levels were evaluated in PBMCs by qPCR (Thermo Fisher). Results: 20 variants, spread over a 8300-Kb region on chromosome 5, were identified in 12 genes, including the low frequency rs13158382 located upstream of the MIR143/145 genes. Since variants in the promoter of MIR143/145 have been reported to affect their expression and reduced levels of miR-145 have been associated with high vWF, the potential correlation between rs13158382 and vWF levels was evaluated. Lower levels of both miRNAs and higher level of vWF mRNA were measured in family members carrying the variant (n=3) compared to family members without the variant (n=3). Analysis of genetic and expression data from of a larger cohort of individuals from the 1000 Genomes and GEUVADIS project confirmed a statistically significant reduction (p=0.023) of miR-143 in heterozygous subjects (n=35) compared to homozygous wild-type individuals (n=386). Since low levels of pri-miRNA-143/145 were measured in heterozygous family members and structural changes of pre-miR-143 with rs13158382 was predicted by miRVaS tool, the reduction of mature miRNAs might result from a lowered synthesis of pri-miRNAs and/or from an aberrant processing of pre-miRNA. Conclusion: This family-based study revealed a new genetic variant potentially involved in vWF increase by reducing the expression of miR-143/145.

Abstract 16457: Characterization of LTBP2 Mutation in Causing Mitral Valve Prolapse

Introduction: Mitral Valve Prolapse (MVP) is a cardiac valvular disorder often associated with significant morbidity and mortality with a prevalence of 2.4% in the general population. Familial studies of MVP suggest an autosomal dominant model of inheritance with incomplete penetrance. Hypothesis: The aim of the current study was to identify a genetic etiology for MVP through trait segregation in a progeny with MVP. Methods: We used exome sequencing and segregation analysis to identify mutations linked to MVP in a progeny which includes members. We then generated two strains of mice using Crisper-Cas9 technology, a complete knockout and a knock-in mouse of the top candidate mutation. At 6 months of age echocardiography was done, the mice were sacrificed and the valves were examined pathologically as well as histologically by Movat pentachrome staining. The readers of both the echo and histology were blinded to the genotype. Results: Of 11 genes with rare deleterious mutations only LTBP2 Val1506Met variant (minor allele frequency of 0.0001) segregated with the trait with a LOD score of 1.5[-DR1] . Knockout mice were more likely to demonstrate myxomatous changes by histology (7 of 9 vs 2 of 6 animals, p=0.03) and echocardiography (14 of 22 vs 1 of 8, p=0.01). Knock-in mice demonstrated significantly higher phenotype rate by histology (8 of 8 vs 0 of 7, p<0.0005) and higher nominal phenotype by echo (4 of10 vs 1 of 9, p=0.2). Conclusions: LTBP2 Val1506Met variant segregated with MVP in a large pedigree. Animal models that recapitulate the phenotype suggest that the mutation is indeed pathogenic and leads to myxomatous valvular change.

A novel autosomal dominant ERLIN2 variant activates endoplasmic reticulum stress in a Chinese HSP family.

Hereditary spastic paraplegia (HSP) has been reported rarely because of a monoallelic variant in ERLIN2. The present study aimed at describing a novel autosomal dominant ERLIN2 pedigree in a Chinese family and exploring the possible mechanism of HSP caused by ERLIN2 variants. The proband and his family underwent a comprehensive medical history inquiry and neurological examinations. Whole-exome sequencing was performed on the proband, and Sanger sequencing was performed on some family members. HeLa cell lines and mouse primary cortical neurons were used for immunofluorescence (IF) and reverse transcription-PCR (RT-PCR). Seven patients were clinically diagnosed with pure spastic paraplegia in four consecutive generations with the autosomal dominant inheritance model. All patients presented juvenile-adolescent onset and gradually worsening pure HSP phenotype. Whole-exome sequencing of the proband and Sanger sequencing of all available family members identified a novel heterozygous c.212 T>C (p.V71A) variant in exon 8 of the ERLIN2 gene. The c.212 T>C demonstrated a high pathogenic effect score through functional prediction. RT-PCR and IF analysis of overexpressed V71A revealed an altered ER morphology and increased XBP-1S mRNA levels, suggesting the activation of ER stress. Overexpression of V71A in primary cultured cortical neurons promoted axon growth. The novel c.212 T>C heterozygous variant in human ERLIN2 caused pure HSP. Moreover, c.212 T>C heterozygous variant in ERLIN2 increased ER stress and affected axonal development.

Wg/Wnt1 and Erasp link ER stress to proapoptotic signaling in an autosomal dominant retinitis pigmentosa model

The endoplasmic reticulum (ER) is a subcellular organelle essential for cellular homeostasis. Perturbation of ER functions due to various conditions can induce apoptosis. Chronic ER stress has been implicated in a wide range of diseases, including autosomal dominant retinitis pigmentosa (ADRP), which is characterized by age-dependent retinal degeneration caused by mutant rhodopsin alleles. However, the signaling pathways that mediate apoptosis in response to ER stress remain poorly understood. In this study, we performed an unbiased in vivo RNAi screen with a Drosophila ADRP model and found that Wg/Wnt1 mediated apoptosis. Subsequent transcriptome analysis revealed that ER stress-associated serine protease (Erasp), which has been predicted to show serine-type endopeptidase activity, was a downstream target of Wg/Wnt1 during ER stress. Furthermore, knocking down Erasp via RNAi suppressed apoptosis induced by mutant rhodopsin-1 (Rh-1P37H) toxicity, alleviating retinal degeneration in the Drosophila ADRP model. In contrast, overexpression of Erasp resulted in enhanced caspase activity in Drosophila S2 cells treated with apoptotic inducers and the stabilization of the initiator caspase Dronc (Death regulator Nedd2-like caspase) by stimulating DIAP1 (Drosophila inhibitor of apoptosis protein 1) degradation. These findings helped identify a novel cell death signaling pathway involved in retinal degeneration in an autosomal dominant retinitis pigmentosa model.

Ouabain Treatment Increases Cyst Progression in a Slowly Progressive Autosomal Dominant Polycystic Kidney Disease Mouse Model

Ouabain Treatment Increases Cyst Progression in a Slowly Progressive Autosomal Dominant Polycystic Kidney Disease Mouse Model

Syndromic cardiac disorder is associated with a non-coding deletion that induces a 3D chromatin remodeling and PITX2 expression dysregulation

Abstract In a first family (family#1), we identified 53 members of whom 17 present a syndromic cardiac disorder characterized by electrical disorders (sinus node dysfunction, atrial fibrillation...) and developmental defects (atrial septal defect, valvopathy, left ventricle non-compaction...) following an autosomal dominant model. Among the affected family members, 6 are implanted with a pacemaker and one experienced a sudden death at 43yo. Despite a strong linkage pointing to the 4q25 region, exome sequencing failed to identify causal variant. Interestingly, 6 additional non-related families presenting the same phenotype have been also identified. Our aims are to identity the causal mutation and the molecular mechanism underlying this complex cardiac syndrome. Genetic study has been performed using whole genome sequencing (WGS). Based on transgenic mouse strains, we assessed the impact of Family#1 mutation on the phenotype and on gene expression. Then, we generated human cardiomyocytes derived iPS cells (CM-iPS) isogenic models to evaluate the epigenome (CUT&RUN and ATAC-seq), transcriptome (RNA-seq) and topological associated domain (TAD) remodelling (Hi-C). By WGS we uncovered a deletion of 15kb in a gene desert area on 4q25, segregating in all affected relatives of Family#1. The 6 other families present overlapping deletions. Mouse model recapitulates the cardiac phenotype and exhibit a dysregulation of Pitx2 expression in cardiac specific compartments. Based on human CM-iPS models, epigenetic data highlight among the 15kb deletion a unique open region containing a CTCF binding site, crucial for delimiting TAD boundaries. Hi-C assay reveals the fusion of 2 TADs and highlights new interactions between PITX2 and atrial specific regulatory elements. We identified a deletion located within a gene desert area associated with a complex cardiac disorder. The CTCF binding site contained in the deletion seems key in the TAD border. The TAD remodelling leads to new (regulatory) interactions and expression dysregulation of PITX2. We describe a new molecular mechanism implying a yet unidentified non-coding regulatory element of PITX2 and responsible for a complex electrical and developmental cardiac syndrome. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Nantes UniversitéFrench national reserch agency (ANR)

Non-coding deletion induces 3D chromatin remodelling and PITX2 expression dysregulation associated with a new syndromic cardiac disorder

In a first family (family#1), we identified 53 members of whom 17 present a new syndromic cardiac disorder characterized by electrical disorders (sinus node dysfunction, atrial fibrillation..) and developmental defects (atrial septal defect, valvopathy, left ventricle non-compaction..) following an autosomal dominant model. Six are implanted with a pacemaker and one experienced a sudden death at 43yo. Interestingly, 6 additional non-related families presenting the same phenotype have been also identified. Our aims are to identity the causal mutation and the molecular mechanism underlying this complex cardiac syndrome. Genetic study has been performed using whole genome sequencing (WGS). Based on transgenic mouse strains, we assessed the impact of Family#1 mutation on the phenotype and on gene expression. Then, we generated human cardiomyocytes derived iPS cells (CM-iPS) isogenic models to evaluate the epigenome (CUT&RUN and ATAC-seq), transcriptome (RNA-seq) and topological associated domain (TAD) remodelling (Hi-C). By WGS we uncovered a deletion of 15 kb in a gene desert area on 4q25, segregating in all affected relatives of Family#1. The 6 other families present overlapping deletions. Mouse model recapitulates the cardiac phenotype and exhibit an increase of Pitx2 expression in right atria, unchanged in left atria and a decrease in ventricle. Based on human CM-iPS models, epigenetic data highlight among the 15 kb deletion a unique open region containing a CTCF binding site, crucial for delimiting TAD boundaries. Hi-C assay reveals the fusion of 2 TADs and highlights new interactions between PITX2 and atrial specific regulatory elements. We identified a deletion located within a gene desert area associated with a new complex cardiac disorder. The CTCF binding site contained in the deletion seems key for the TAD border. The TAD remodelling leads to new (regulatory) interactions and expression dysregulation of PITX2. We describe a new molecular mechanism implying a yet unidentified non-coding regulatory element of PITX2 and responsible for a complex electrical and developmental cardiac syndrome.

BS-515-01 NON-CODING DELETION INDUCES 3D CHROMATIN REMODELLING AND PITX2 EXPRESSION DYSREGULATION ASSOCIATED WITH A SYNDROMIC CARDIAC DISORDER

In a first family (family#1), we identified 53 members of whom 17 present a syndromic cardiac disorder characterized by electrical disorders (sinus node dysfunction, atrial fibrillation...) and developmental defects (atrial septal defect, valvopathy, left ventricle non-compaction...) following an autosomal dominant model. Among the affected family members, 6 are implanted with a pacemaker and one experienced a sudden death at 43yo. Despite a strong linkage pointing to the 4q25 region, exome sequencing failed to identify causal variant.

Rare and Common Variants in KIF15 Contribute to Genetic Risk of Idiopathic Pulmonary Fibrosis.

Rationale: Genetic studies of idiopathic pulmonary fibrosis (IPF) have improved our understanding of this disease, but not all causal loci have been identified. Objectives: To identify genes enriched with rare deleterious variants in IPF and familial pulmonary fibrosis. Methods: We performed gene burden analysis of whole-exome data, tested single variants for disease association, conducted KIF15 (kinesin family member 15) functional studies, and examined human lung single-cell RNA sequencing data. Measurements and Main Results: Gene burden analysis of 1,725 cases and 23,509 control subjects identified heterozygous rare deleterious variants in KIF15, a kinesin involved in spindle separation during mitosis, and three telomere-related genes (TERT [telomerase reverse transcriptase], RTEL1 [regulator of telomere elongation helicase 1], and PARN [poly(A)-specific ribonuclease]). KIF15 was implicated in autosomal-dominant models of rare deleterious variants (odds ratio [OR], 4.9; 95% confidence interval [CI], 2.7-8.8; P = 2.55 × 10-7) and rare protein-truncating variants (OR, 7.6; 95% CI, 3.3-17.1; P = 8.12 × 10-7). Meta-analyses of the discovery and replication cohorts, including 2,966 cases and 29,817 control subjects, confirm the involvement of KIF15 plus the three telomere-related genes. A common variant within a KIF15 intron (rs74341405; OR, 1.6; 95% CI, 1.4-1.9; P = 5.63 × 10-10) is associated with IPF risk, confirming a prior report. Lymphoblastoid cells from individuals heterozygous for the common variant have decreased KIF15 and reduced rates of cell growth. Cell proliferation is dependent on KIF15 in the presence of an inhibitor of Eg5/KIF11, which has partially redundant function. KIF15 is expressed specifically in replicating human lung cells and shows diminished expression in replicating epithelial cells of patients with IPF. Conclusions: Both rare deleterious variants and common variants in KIF15 link a nontelomerase pathway of cell proliferation with IPF susceptibility.

More autosomal dominant SPG18 cases than recessive? The first AD-SPG18 pedigree in Chinese and literature review.

ObjectiveHereditary spastic paraplegia (HSP) due to ERLIN2 gene mutations was designated as spastic paraplegia 18 (SPG18). To date, SPG18 families/cases are still rarely reported. All early reported cases shared the autosomal recessive (AR) inheritance pattern. Over the past 3 years, autosomal dominant (AD) or sporadic SPG18 cases had been continuously reported. Here, we reported the clinical and genetic features of the first autosomal dominant SPG18 pedigree in Chinese.MethodsWe conducted detailed medical history inquiry, neurological examinations of the proband and his family members, and charted the family tree. The proband underwent brain and cervical magnetic resonance imaging (MRI), electromyography (EMG), and whole exome sequencing. Sanger sequencing was performed to verify the genetic variation in the proband and some family members. A literature review of all reported SPG18 families/cases was carried out to summarize the clinical‐genetic characteristics of SPG18 under different inheritance patterns.ResultsFour patients were clinically diagnosed as chronic spastic paraplegia in three consecutive generations with the autosomal dominant inheritance model. All the patients presented juvenile‐adolescent onset and gradually worsening pure HSP phenotype. Clinical phenotypes were consistent within the family. Whole exome sequencing in the proband identified a previously reported heterozygous c.502G > A (p.V168M) mutation in exon 8 of ERLIN2 gene. This mutation was cosegregated with the phenotype in the family and was classified as likely pathogenic according to American College of Medical Genetics and Genomics (ACMG) guidelines. To date, eight AR‐SPG18 families, five AD‐SPG18 families, and three sporadic cases had been reported. Clinical phenotype of AD‐SPG18 was juvenile‐adolescent onset pure HSP, while the phenotype of AR‐SPG18 was mostly complicated HSP with earlier onset and more severe conditions. In rare cases, the initial spastic paraplegia could evolve to rapidly progressive amyotrophic lateral sclerosis (ALS).ConclusionsWe reported the first autosomal dominant SPG18 pedigree in Chinese Han population, which added more pathogenic evidence for V168M mutation. As more SPG18 cases reported, the essentials of SPG18 need to be updated in clinical practice. Special attentions should be given in gene test for upper motor neuron disorders in case of missing heterozygous mutations in ERLIN2.

Clusterin enhances cell survival by suppressing neuronal nitric-oxide synthase expression in the rhodopsin S334ter-line3 retinitis pigmentosa model

Environmental changes in the retina, including oxidative stress-induced cell death, influence photoreceptor degeneration in Retinitis Pigmentosa (RP). Previously, we tested and discovered that a cytoprotective chaperone protein, clusterin, produced robust preservation of rod photoreceptors of a rat autosomal dominant rhodopsin transgenic model of RP, S334ter-line3. To investigate the biochemical and molecular cytoprotective pathways of clusterin, we examined and compared a known source of cone cell death, nitric oxide (NO), observing nNOS expression using antibody against nNOS in RP retinas with intravitreal injections of saline, clusterin (10 μg/ml), or a non-isoform-selective NOS inhibitor (25 mM), L-NAME, or with an intraperitoneal injection (IP) of L-NAME (100 mg/kg). Rhodopsin-immunoreactive rod photoreceptor cells and nNOS-immunoreactive cells were quantified with immunohistochemistry in the presence or absence of L-NAME or clusterin, and the total nNOS retinal expression was determined by immunoblot analysis. In this study, the level of nNOS expression was significantly up-regulated postnatally (P) at P15 (P < 0.05), P30 (P < 0.001) and P60 (P < 0.0001) in RP retinas compared to normal controls. Clusterin treatment suppressed the up-regulated nNOS expression in RP retinas (P < 0.0001) and was enhanced in Type II amacrine cells. Additionally, IP injection of L-NAME at P15 prolonged rod survival in the later stage of RP retinas (P < 0.001). Conversely, rod survival in L-NAME–treated RP retinas was not equivalent to the rod survival number seen in clusterin-treated retinas, which suggests induction of nNOS expression in RP retinas and its reduction by clusterin is only partly responsible for the rescue observed through the reduction of nNOS expression in S334ter-line3 rat retinas.

Drug screening with zebrafish visual behavior identifies carvedilol as a potential treatment for an autosomal dominant form of retinitis pigmentosa

Retinitis Pigmentosa (RP) is a mostly incurable inherited retinal degeneration affecting approximately 1 in 4000 individuals globally. The goal of this work was to identify drugs that can help patients suffering from the disease. To accomplish this, we screened drugs on a zebrafish autosomal dominant RP model. This model expresses a truncated human rhodopsin transgene (Q344X) causing significant rod degeneration by 7 days post-fertilization (dpf). Consequently, the larvae displayed a deficit in visual motor response (VMR) under scotopic condition. The diminished VMR was leveraged to screen an ENZO SCREEN-WELL REDOX library since oxidative stress is postulated to play a role in RP progression. Our screening identified a beta-blocker, carvedilol, that ameliorated the deficient VMR of the RP larvae and increased their rod number. Carvedilol may directly on rods as it affected the adrenergic pathway in the photoreceptor-like human Y79 cell line. Since carvedilol is an FDA-approved drug, our findings suggest that carvedilol can potentially be repurposed to treat autosomal dominant RP patients.

Molecular mechanism of a new cardiac syndrome associated with a regulatory element deletion of chromosome 4q25

Abstract Introduction We identified a large family of 53 members of whom 22 present a new cardiac syndrome characterized by electrical disorders and developmental defects following an autosomal dominant model. Among the affected family members 6 are implanted with a pacemaker, 2 experienced syncope and one a sudden death at 43yo. Linkage analysis points, with high confidence, to the chromosome 4q25 region. This region is associated with the Ankyrin syndrome (mutation in ANK2) sharing partly the electrical defects observed in the affected family members. No mutation was found in the coding region of the 4q25 region as well as in the coding and non-coding part of the ANK2. Objective Our aims are first to identity the responsible mutation present in this family and understand the molecular mechanisms leading to this new syndrome. Method Whole genome sequencing (WGS) has been employed to identify genetic variants responsible for this syndrome. ChIP-seq and ATAC-seq were used for functional annotation and genome editing (CRISPR-Cas9) to generate iPS cellular models. Results By WGS we uncovered a deleted region of 15kb in a gene desert area on 4q25, segregating in all affected relatives. Five other families (3 French and 2 Japanese) presenting the same phenotype show overlapping deletions. We generated human cardiac epigenetic data and identified among the 15kb deleted region a unique active enhancer region within the presence of a transcript factor CTCF binding site. Isogenic cell lines where the 15kb and the CTCF binding have been deleted are under investigation. Conclusion We identified a new cardiac syndrome and for the first time a mutation located within a gene desert area leading to severe and complex cardiac disorders. We demonstrated the presence of a likely gene regulatory element. Experiments are ongoing to characterize the molecular mechanisms and consequence of the deletion on gene expression. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Pays de la loire - Etoiles montantes

Introduction of a de novo Creb-binding protein gene mutation in sperm to produce a Rubinstein-Taybi syndrome model using inbred C57BL/6 mice

Neurodevelopmental disorders, including intellectual disability and autism spectrum disorder, are often caused by de novo autosomal dominant mutations. While mouse models are frequently used to investigate these disorders, the genetic background sometimes affects the appearance or severity of mutant phenotypes. In a previous report, we developed a system to produce de novo heterozygous mutant mice using the Cre-LoxP system without the need to maintain the heterozygous mutant line itself (Takagi et al. 2015). To further verify the applicability of the de novo mutation system in sperm, we used this system to produce a mouse model for Rubinstein-Taybi syndrome, using a Cbp heterozygous mutant, which has been reported to be difficult to maintain on a C57BL/6 background. Here, we show that de novo Cbp- loss-of-function heterozygous mutant mice with a C57BL/6 background, present with a clear craniofacial phenotype and reduced locomotor activity in the open field test, which was not observed in the loss-of-function of Cbp heterozygous mutant line mice with a mixed genetic background, but was observed in the dominant negative Cbp heterozygous mutant line with a mixed genetic background. Meanwhile, the de novo heterozygous Cbp mutant mice still showed great variability in survival rates despite their inbred background. These results further confirmed that the de novo mutation system used in germ cells is effective for stable production and analysis of an autosomal dominant disorder mouse model, which is often difficult to maintain as a mutant mouse line.

Abstract 37: Highly aggregated lung cancer families reveal a heterogeneous cause for a previous linkage signal on 6q

Abstract More Americans die every year of lung cancer than any other cancer. While the environmental risks for lung cancer are well understood, the genetic risk factors for this disease are not, even though it has been shown that lung cancer risk aggregates in families. Segregation analyses have confirmed the likelihood of rare, highly penetrant variants affecting lung cancer. Family studies offer a unique opportunity to identify such rare risk variants. We have previously identified a genome-wide significant risk locus for lung cancer using multipoint linkage analysis in highly aggregated lung cancer families. In this study, we performed targeted sequencing on this 6q23-6q27 region on 75 individuals from the 9 most strongly linked families. Parametric two-point linkage analysis using an autosomal dominant model with 10% penetrance for carriers and a 1% phenocopy rate and disease allele frequency of 1% was performed for each family. While we did not find any genome-wide significant results in any of the individual families, we did observe several interesting potential rare risk variants. First, we observed that the significant signal previously observed on 6q is recapitulated in these data but the location of the peak LOD is highly heterogeneous across families and it is likely that each family has a different risk gene. While most of the highest LOD scores were in noncoding variants, we did observe exonic variants with the highest LOD scores in two families (44 and 42). Both variants were rare, with a minor allele frequency (MAF) of approximately 1% and were in LPA and GPR126 respectively. Both these genes have been implicated somatically in lung cancer, however this is the first time that they have been implicated in the germline. While the other families have their highest LOD scores in noncoding variants, some of these genes are also good potential candidate genes including PARK2 (family 30), GRM1 (family 47), and PDE10A (family 102). All three genes have been implicated in lung cancer in some capacity, and this is the first time that GRM1 and PDE10A have been implicated as germline mutations. Again, all these variants are rare (MAF ⇐ 0.01) in the general population, which makes sense for a potential highly penetrant risk variant. In this study, we have elucidated that a previously identified risk locus on 6q25 is heterogeneous in the nine most strongly linked families, with different families appearing to be carrying different risk variants. Many of the top variants in each family are rare variants that are in good potential causal genes that have been identified for the first time here as germline risk variants for lung cancer. Further functional annotation is underway for these variants and some additional linkage analyses using other penetrance matrices may also be performed. Citation Format: Anthony M. Musolf, Claire L. Simpson, Bilal A. Moiz, Mariza de Andrade, Diptasri Mandal, Colette Gaba, Ping Yang, Ming You, Elena Y. Kupert, Marshall W. Anderson, Ann G. Schwartz, Susan M. Pinney, Christopher I. Amos, Joan E. Bailey-Wilson. Highly aggregated lung cancer families reveal a heterogeneous cause for a previous linkage signal on 6q [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 37.

ANALYSIS OF ASSOCIATION OF rs9536314 OF THE KL GENE WITH ANTHROPOMETRIC AND BIOCHEMICAL INDICATORS IN MEN OF NOVOSIBIRSK (WEST SIBERIA)

Purpose of the study. To determine the frequency of the rs9536314 (F325V) polymorphism of the KL gene and the association of this variant with a number of biochemical and anthropometric parameters in men of the study group and in the Caucasian population of Western Siberia. Materials and methods. The study group (69 men, average age 61.2 ±11.5 years) was randomly formed from a sample of persons who applied to the clinic and polyclinic of NIITPM - a branch of the ICG SB RAS and GBUZ NSO Hospital of war veterans No. 3 (178 men, aged 50-65 years old and over 80 years old). The population group was randomly selected (219 people) from the sample surveyed within the framework of the International Multicenter Project Risk Factors for Cardiovascular Diseases in Eastern Europe HAPIEE (9360 participants, 45–69 years old, mean age 53.8±7 years old, Caucasians > 90 %). Biochemical parameters were determined by standard enzymatic methods. Serum concentration of Klotho protein was measured by ELISA. Genomic DNA was amplified by polymerase chain reaction in a standard reaction mixture and further digested with TaqI B restriction enzyme. Results. The frequency of genotypes (TT, TG, and GG) and alleles (T and G) rs9536314 of the KL gene in the study group corresponds to the data in the population of Western Siberia, as well as the population of Western and Eastern Europe. There were no statistically significant differences in the mean values of the studied clinical and biochemical parameters depending on the rs9536314 genotypes of the KL gene in the study group and in the population. In the study group, the level of Klotho protein in the blood and the glomerular filtration rate in men with coronary heart disease and arterial hypertension did not differ in the autosomal dominant and autosomal recessive models for the rs9536314 KL gene. Conclusion . Thus, the frequency of the rs9536314 polymorphism of the KL gene in the study group corresponds to the frequency of the rs9536314 polymorphism of the KL gene in the Caucasian population of Western Siberia. Biochemical and anthropometric parameters, as well as the Klotho protein, do not have statistically significant differences depending on the genotypes of rs9536314 of the KL gene in the examined men.

Unfolding Remedial Targets for Alzheimer's Disease

Dementia also termed as memory loss is due to the functional impairment of behavior and cognition in people aged 65 years and above. Alzheimer's disease (AD) is the most occurring neurodegenerative disorder around the globe and its estimated that about 47 million people are affected by this disease and is expected to increase to 62% by the end of 2030. It is characterized by the intracellular neuro-fibrillary tangles, extracellular amyloid plaques, and deficiency cholinergic neurons and cholinergic transmission. Alzheimer's disease is due to many reasons. The early-onset Alzheimer's disease, an uncommon form of disease, which pursues an autosomaldominant model in most of cases with mutations recognized in amyloid precursor protein (APP), presenilin (PS) 1 and 2. The late-onset Alzheimer's disease, an erratic form of disease, which affects over 90% of patients with different genetic makeup and the associated risk factors are studied by different genetic studies and bioinformatic methods. These findings gave us deeper insights about the pathogenesis of Alzheimer's disease and also in the advancement of newer therapeutic pathways and clinical trial designs. Presently available drugs are gives only symptomatic relief to the patients such as reversible acetylcholinestrase inhibitors Donepezil, Rivastigmine, Galantamine and N-methyl D-aspartate receptor antagonist like Memantine. Many compounds are still under preclinical and clinical studies focusing on the pathology of Alzheimer's. The Recent studies target the formation and aggregation of amyloid plaques, inhibition of tau formation, stabilization of tau proteins, gene therapy and stem cell therapy. In this review summarises the current management and new approaches in the management of Alzheimer's disease.

Ciliary exclusion of Polycystin-2 promotes kidney cystogenesis in an autosomal dominant polycystic kidney disease model

The human PKD2 locus encodes Polycystin-2 (PC2), a TRPP channel that localises to several distinct cellular compartments, including the cilium. PKD2 mutations cause Autosomal Dominant Polycystic Kidney Disease (ADPKD) and affect many cellular pathways. Data underlining the importance of ciliary PC2 localisation in preventing PKD are limited because PC2 function is ablated throughout the cell in existing model systems. Here, we dissect the ciliary role of PC2 by analysing mice carrying a non-ciliary localising, yet channel-functional, PC2 mutation. Mutants develop embryonic renal cysts that appear indistinguishable from mice completely lacking PC2. Despite not entering the cilium in mutant cells, mutant PC2 accumulates at the ciliary base, forming a ring pattern consistent with distal appendage localisation. This suggests a two-step model of ciliary entry; PC2 first traffics to the cilium base before TOP domain dependent entry. Our results suggest that PC2 localisation to the cilium is necessary to prevent PKD.