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(exome OR "exome sequencing") AND disease

These pubmed results were generated on 2018/10/03

PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

16 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

(exome OR "exome sequencing") AND disease

These pubmed results were generated on 2018/10/03

PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Accurate and sensitive analysis of minimal residual disease in acute myeloid leukemia using deep sequencing of single nucleotide variations.

J Mol Diagn. 2018 Sep 28;:

Authors: Malmberg ED, Rehammar A, Pereira MB, Abrahamsson J, Samuelsson T, Ståhlman S, Asp J, Tierens A, Palmqvist L, Kristiansson E, Fogelstrand L

Abstract
Minimal residual disease (MRD) in acute myeloid leukemia (AML) is of major prognostic importance. The genetic landscape of AML is characterized by numerous somatic mutations, which constitute potential MRD markers. Leukemia-specific mutations can be identified with exome sequencing at diagnosis and assessed during follow-up at low frequencies using targeted deep sequencing. Our aim was to further validate this patient-tailored assay for substitution mutations. By applying a statistical model, which corrects for position-specific errors, a limit of detection for single nucleotide variations of variant allele frequency (VAF) 0.02% was achieved. The assay was linear in MRD range (0.03% to 1%) with good precision (CV 4.1% (2.2% to 5.7%) at VAF 1% and 13.3% (8.8% to 19.4%) at VAF 0.1%), and low relative bias (7.9% (2.5% o 15.3%) at VAF 1%). When applied to six childhood AML cases and compared to multiparameter flow cytometry (MFC) for MRD analysis, deep sequencing showed concordance and superior sensitivity. There was further a high concordance with expression of fusion transcripts RUNX1-RUNX1T1 and KMT2A-MLLT10. The deep sequencing assay also detected mutations in blood when VAF in bone marrow exceeded 0.1% (n=19). In conclusion, deep sequencing enables reliable detection of low levels of residual leukemic cells. Introduction of this method in patient care will allow for highly sensitive MRD surveillance in virtually every patient with AML.

PMID: 30273780 [PubMed - as supplied by publisher]

Co-existence of endometriosis with 13 non-gynecological co-morbidities: Mutation analysis by whole exome sequencing.

Mol Med Rep. 2018 Oct 01;:

Authors: Matalliotaki C, Matalliotakis M, Zervou MI, Trivli A, Matalliotakis I, Mavromatidis G, Spandidos DA, Albertsen HM, Chettier R, Ward K, Goulielmos GN

Abstract
Endometriosis is an enigmatic condition with an unknown etiology and poorly understood pathogenesis and women with endometriosis represent a high-risk population group for a large category of chronic conditions. The study focused on a 67-year-old woman who presented with a 40-year history of familial endometriosis associated with various non-gynecological co-morbidities, thus representing a unique case from a cohort of 1,000 patients with endometriosis. Her family history included infertile members suffering from endometriosis. Thirteen non-gynecological co-morbidities were documented throughout the years, including five autoimmune diseases (i.e., systemic lupus erythematosus, ankylosing spondylitis, multiple sclerosis, bronchial asthma and Crohn's disease), urinary bladder diverticulum, osteoporosis, multinodular goiter, cardiovascular diseases, gastroesophageal reflux disease, malignant tumor of urinary bladder, Barrett's esophagus and bilateral cataract. In order to understand the potential role of gene mutations in the development of all those co-morbidities, whole exome sequencing was performed and the presence of various disease-associated, potentially causal missense variants, were observed. These findings are in accordance with the previously suggested common underlying etiologic pathway for some, but not all, autoimmune disorders. This unusual case provides novel insights demonstrating that endometriosis can coexist with various chronic autoimmune diseases and other conditions, including non-gynecological malignancies, which possibly share a common genetic cause, a fact that should be taken into consideration seriously by clinicians.

PMID: 30272298 [PubMed - as supplied by publisher]

A family with hypothyroidism caused by fatty acid synthase and apolipoprotein B receptor mutations.

Mol Med Rep. 2018 Sep 20;:

Authors: Sun J, Sun L, Chen W, Yin X, Lu Y, Jiang Q

Abstract
Hypothyroidism is a disease with a genetic component. The present study aimed to identify the potential causative gene mutation in a family with hypothyroidism and to investigate its potential pathology. DNA was extracted from the affected individual and his parents, maternal aunt and maternal grandmother. Whole exome sequencing was used to examine their exomes. The potential causative genes that may have an autosomal dominant mode of inheritance were selected after variant calling and filtering. Bioinformatics analysis was utilized to predict the deleteriousness of the identified variants, and multiple sequence alignment and conserved protein domain analyses were performed using online software. Finally, Sanger sequencing was used to validate the identified variants. In the present study, a total of 50 variants were screened based on the autosomal dominant mode of inheritance. Two variants, the fatty acid synthase (FASN) and apolipoprotein B receptor (APOBR) genes, were further analyzed, as they were highly associated with hypothyroidism. Genotyping results revealed that two mutations, c.G7192T (p.A2398S) in the FASN gene and c.C1883G (p.T628R) in the APOBR gene, were fully co‑segregated with established hypothyroidism phenotypes in the family. These mutations were located in the conserved α/β‑hydrolase fold and Na+/Ca2+ exchanger superfamily domain of FASN and APOBR, respectively. In conclusion, the present study demonstrated that the FASN c.G7192T and APOBR c.C1883G mutations may be the potential causative variants in this Chinese hypothyroidism pedigree.

PMID: 30272292 [PubMed - as supplied by publisher]

The Genetics of Clinical Liver Diseases: Insight into the TM6SF2 E167K Variant.

J Clin Transl Hepatol. 2018 Sep 28;6(3):326-331

Authors: Zhang X, Liu S, Dong Q, Xin Y, Xuan S

Abstract
The transmembrane 6 superfamily member 2 (TM6SF2) gene E167K variant (rs58542926) was identified by exome-wide association study as a nonsynonymous single nucleotide polymorphism associated with nonalcoholic fatty liver disease. The TM6SF2 E167K variant features a C-to-T substitution at nucleotide 499, encoding a glutamate with lysine change at codon 167 (E167K). TM6SF2 is markedly expressed in the liver, small intestine and kidney, and has been proposed as an important risk factor for diseases associated with lipid metabolism. Subsequently, multifunctional studies of the TM6SF2 E167K variant have been carried out in a spectrum of liver diseases, such as nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, fibrosis, cirrhosis, and viral hepatitis. This review summarizes the research status of the TM6SF2 E167K variant in different liver diseases and specific populations, and discusses the potential mechanisms of the TM6SF2 E167K variant's role in the progression of various liver diseases.

PMID: 30271746 [PubMed]

Novel methionyl-tRNA synthetase gene variants/phenotypes in interstitial lung and liver disease: A case report and review of literature.

World J Gastroenterol. 2018 Sep 28;24(36):4208-4216

Authors: Abuduxikuer K, Feng JY, Lu Y, Xie XB, Chen L, Wang JS

Abstract
Interstitial lung and liver disease (ILLD) is caused by biallelic mutations in the methionyl-tRNA synthetase (MARS) gene. To date, no genetic changes other than missense variants were reported in the literature. Here, we report a five-month old female infant with typical ILLD (failure to thrive, developmental delay, jaundice, diffuse interstitial lung disease, hepatomegaly with severe steatosis, anemia, and thrombocytosis) showing novel phenotypes such as kidney stones, acetabular dysplasia, prolonged fever, and extreme leukocytosis. Whole exome sequencing revealed a novel truncating variant (c.2158C>T/p.Gln720Stop) together with a novel tri-nucleotide insertion (c.893_894insTCG that caused the insertion of an arginine at amino acid position 299) in the MARS gene.

PMID: 30271085 [PubMed - in process]

Recall by genotype and cascade screening for familial hypercholesterolemia in a population-based biobank from Estonia.

Genet Med. 2018 Oct 01;:

Authors: Alver M, Palover M, Saar A, Läll K, Zekavat SM, Tõnisson N, Leitsalu L, Reigo A, Nikopensius T, Ainla T, Kals M, Mägi R, Gabriel SB, Eha J, Lander ES, Irs A, Philippakis A, Marandi T, Natarajan P, Metspalu A, Kathiresan S, Esko T

Abstract
PURPOSE: Large-scale, population-based biobanks integrating health records and genomic profiles may provide a platform to identify individuals with disease-predisposing genetic variants. Here, we recall probands carrying familial hypercholesterolemia (FH)-associated variants, perform cascade screening of family members, and describe health outcomes affected by such a strategy.
METHODS: The Estonian Biobank of Estonian Genome Center, University of Tartu, comprises 52,274 individuals. Among 4776 participants with exome or genome sequences, we identified 27 individuals who carried FH-associated variants in the LDLR, APOB, or PCSK9 genes. Cascade screening of 64 family members identified an additional 20 carriers of FH-associated variants.
RESULTS: Via genetic counseling and clinical management of carriers, we were able to reclassify 51% of the study participants from having previously established nonspecific hypercholesterolemia to having FH and identify 32% who were completely unaware of harboring a high-risk disease-associated genetic variant. Imaging-based risk stratification targeted 86% of the variant carriers for statin treatment recommendations.
CONCLUSION: Genotype-guided recall of probands and subsequent cascade screening for familial hypercholesterolemia is feasible within a population-based biobank and may facilitate more appropriate clinical management.

PMID: 30270359 [PubMed - as supplied by publisher]

Clinical utility of the polygenic LDL-C SNP score in familial hypercholesterolemia.

Atherosclerosis. 2018 Oct;277:457-463

Authors: Futema M, Bourbon M, Williams M, Humphries SE

Abstract
Mutations in any of three genes (LDLR, APOB and PCSK9) are known to cause autosomal dominant FH, but a mutation can be found in only ∼40% of patients with a clinical diagnosis of FH. In the remainder, a polygenic aetiology may be the cause of the phenotype, due to the co-inheritance of common LDL-C raising variants. In 2013, we reported the development of a 12-SNP LDL-C "SNP-Score" based on common variants identified as LDL-C raising from genome wide association consortium studies, and have confirmed the validity of this score in samples of no-mutation FH adults and children from more than six countries with European-Caucasian populations. In more than 80% of those with a clinical diagnosis of FH but with no detectable mutation in LDLR/APOB/PCSK9, the polygenic explanation is the most likely for their hypercholesterolaemia. Those with a low score (in the bottom two deciles) may have a mutation in a novel gene, and further research including whole exome or whole genome sequencing is warranted. Only in families where the index case has a monogenic cause should cascade testing be carried out, using DNA tests for an unambiguous identification of affected relatives. The clinical utility of the polygenic explanation is that it supports a more conservative (less aggressive) treatment care pathway for those with no mutation. The ability to distinguish those with a clinical diagnosis of FH who have a monogenic or a polygenic cause of their hypercholesterolaemia is a paradigm example of the use of genomic information to inform Precision Medicine using lipid lowering agents with different efficacy and costs.

PMID: 30270085 [PubMed - in process]

Whole-Gene Duplication of PCSK9 as a Novel Genetic Mechanism for Severe Familial Hypercholesterolemia.

Can J Cardiol. 2018 Oct;34(10):1316-1324

Authors: Iacocca MA, Wang J, Sarkar S, Dron JS, Lagace T, McIntyre AD, Lau P, Robinson JF, Yang P, Knoll JH, Cao H, McPherson R, Hegele RA

Abstract
BACKGROUND: Familial hypercholesterolemia (FH) is a common genetic disorder of severely elevated low-density lipoprotein (LDL) cholesterol, characterized by premature atherosclerotic cardiovascular disease. Although copy number variations (CNVs) are a large-scale mutation-type capable of explaining FH cases, they have been, to date, assessed only in the LDLR gene. Here, we performed novel CNV screening in additional FH-associated genes using a next-generation sequencing-based approach.
METHODS: In 704 patients with FH, we sequenced FH-associated genes APOB, PCSK9, LDLRAP1, APOE, STAP1, LIPA, and ABCG5/8 using our LipidSeq targeted next-generation sequencing panel. Bioinformatic tools were applied to LipidSeq data for CNV screening, and identified CNVs were validated using whole-exome sequencing and microarray-based copy number analyses.
RESULTS: We identified a whole-gene duplication of PCSK9 in 2 unrelated Canadian FH index cases; this PCSK9 CNV was also found to cosegregate with affected status in family members. Features in affected individuals included severely elevated LDL cholesterol levels that were refractory to intensive statin therapy, pronounced clinical stigmata, premature cardiovascular events, and a plasma PCSK9 of approximately 5000 ng/mL in 1 index case. We found no CNVs in APOB, LDLRAP1, APOE, STAP1, LIPA, and ABCG5/8 in our cohort of 704 FH individuals.
CONCLUSIONS: Here, we report the first description of a CNV affecting the PCSK9 gene in FH. This finding is associated with a profound FH phenotype and the highest known plasma PCSK9 level reported in a human. This finding also has therapeutic relevance, as elevated PCSK9 levels may limit the efficacy of high-dose statin therapy and also PCSK9 inhibition.

PMID: 30269829 [PubMed - in process]

The evolutionary landscape of chronic lymphocytic leukemia treated with ibrutinib targeted therapy.

Nat Commun. 2017 12 19;8(1):2185

Authors: Landau DA, Sun C, Rosebrock D, Herman SEM, Fein J, Sivina M, Underbayev C, Liu D, Hoellenriegel J, Ravichandran S, Farooqui MZH, Zhang W, Cibulskis C, Zviran A, Neuberg DS, Livitz D, Bozic I, Leshchiner I, Getz G, Burger JA, Wiestner A, Wu CJ

Abstract
Treatment of chronic lymphocytic leukemia (CLL) has shifted from chemo-immunotherapy to targeted agents. To define the evolutionary dynamics induced by targeted therapy in CLL, we perform serial exome and transcriptome sequencing for 61 ibrutinib-treated CLLs. Here, we report clonal shifts (change >0.1 in clonal cancer cell fraction, Q < 0.1) in 31% of patients during the first year of therapy, associated with adverse outcome. We also observe transcriptional downregulation of pathways mediating energy metabolism, cell cycle, and B cell receptor signaling. Known and previously undescribed mutations in BTK and PLCG2, or uncommonly, other candidate alterations are present in seventeen subjects at the time of progression. Thus, the frequently observed clonal shifts during the early treatment period and its potential association with adverse outcome may reflect greater evolutionary capacity, heralding the emergence of drug-resistant clones.

PMID: 29259203 [PubMed - indexed for MEDLINE]

Loss-of-activity-mutation in the cardiac chloride-bicarbonate exchanger AE3 causes short QT syndrome.

Nat Commun. 2017 11 22;8(1):1696

Authors: Thorsen K, Dam VS, Kjaer-Sorensen K, Pedersen LN, Skeberdis VA, Jurevičius J, Treinys R, Petersen IMBS, Nielsen MS, Oxvig C, Morth JP, Matchkov VV, Aalkjær C, Bundgaard H, Jensen HK

Abstract
Patients with short QT syndrome (SQTS) may present with syncope, ventricular fibrillation or sudden cardiac death. Six SQTS susceptibility genes, encoding cation channels, explain <25% of SQTS cases. Here we identify a missense mutation in the anion exchanger (AE3)-encoding SLC4A3 gene in two unrelated families with SQTS. The mutation causes reduced surface expression of AE3 and reduced membrane bicarbonate transport. Slc4a3 knockdown in zebrafish causes increased cardiac pHi, short QTc, and reduced systolic duration, which is rescued by wildtype but not mutated SLC4A3. Mechanistic analyses suggest that an increase in pHi and decrease in [Cl-]i shortened the action potential duration. However, other mechanisms may also play a role. Altered anion transport represents a mechanism for development of arrhythmia and may provide new therapeutic possibilities.

PMID: 29167417 [PubMed - indexed for MEDLINE]

Clinical exome sequencing for fetuses with ultrasound abnormalities and a suspected Mendelian disorder.

Genome Med. 2018 Sep 28;10(1):74

Authors: Normand EA, Braxton A, Nassef S, Ward PA, Vetrini F, He W, Patel V, Qu C, Westerfield LE, Stover S, Dharmadhikari AV, Muzny DM, Gibbs RA, Dai H, Meng L, Wang X, Xiao R, Liu P, Bi W, Xia F, Walkiewicz M, Van den Veyver IB, Eng CM, Yang Y

Abstract
BACKGROUND: Exome sequencing is now being incorporated into clinical care for pediatric and adult populations, but its integration into prenatal diagnosis has been more limited. One reason for this is the paucity of information about the clinical utility of exome sequencing in the prenatal setting.
METHODS: We retrospectively reviewed indications, results, time to results (turnaround time, TAT), and impact of exome results for 146 consecutive "fetal exomes" performed in a clinical diagnostic laboratory between March 2012 and November 2017. We define a fetal exome as one performed on a sample obtained from a fetus or a product of conception with at least one structural anomaly detected by prenatal imaging or autopsy. Statistical comparisons were performed using Fisher's exact test.
RESULTS: Prenatal exome yielded an overall molecular diagnostic rate of 32% (n = 46/146). Of the 46 molecular diagnoses, 50% were autosomal dominant disorders (n = 23/46), 41% were autosomal recessive disorders (n = 19/46), and 9% were X-linked disorders (n = 4/46). The molecular diagnostic rate was highest for fetuses with anomalies affecting multiple organ systems and for fetuses with craniofacial anomalies. Out of 146 cases, a prenatal trio exome option designed for ongoing pregnancies was performed on 62 fetal specimens, resulting in a diagnostic yield of 35% with an average TAT of 14 days for initial reporting (excluding tissue culture time). The molecular diagnoses led to refined recurrence risk estimates, altered medical management, and informed reproductive planning for families.
CONCLUSION: Exome sequencing is a useful diagnostic tool when fetal structural anomalies suggest a genetic etiology, but other standard prenatal genetic tests did not provide a diagnosis.

PMID: 30266093 [PubMed - in process]

Early-Onset Invasive Infection Due to Corynespora cassiicola Associated with Compound Heterozygous CARD9 Mutations in a Colombian Patient.

J Clin Immunol. 2018 Sep 28;:

Authors: Arango-Franco CA, Moncada-Vélez M, Beltrán CP, Berrío I, Mogollón C, Restrepo A, Trujillo M, Osorio SD, Castro L, Gómez LV, Muñoz AM, Molina V, Del Río Cobaleda DY, Ruiz AC, Garcés C, Alzate JF, Cabarcas F, Orrego JC, Casanova JL, Bustamante J, Puel A, Arias AA, Franco JL

Abstract
PURPOSE: CARD9 deficiency is an inborn error of immunity that predisposes otherwise healthy humans to mucocutaneous and invasive fungal infections, mostly caused by Candida, but also by dermatophytes, Aspergillus, and other fungi. Phaeohyphomycosis are an emerging group of fungal infections caused by dematiaceous fungi (phaeohyphomycetes) and are being increasingly identified in patients with CARD9 deficiency. The Corynespora genus belongs to phaeohyphomycetes and only one adult patient with CARD9 deficiency has been reported to suffer from invasive disease caused by C. cassiicola. We identified a Colombian child with an early-onset, deep, and destructive mucocutaneous infection due to C. cassiicola and we searched for mutations in CARD9.
METHODS: We reviewed the medical records and immunological findings in the patient. Microbiologic tests and biopsies were performed. Whole-exome sequencing (WES) was made and Sanger sequencing was used to confirm the CARD9 mutations in the patient and her family. Finally, CARD9 protein expression was evaluated in peripheral blood mononuclear cells (PBMC) by western blotting.
RESULTS: The patient was affected by a large, indurated, foul-smelling, and verrucous ulcerated lesion on the left side of the face with extensive necrosis and crusting, due to a C. cassiicola infectious disease. WES led to the identification of compound heterozygous mutations in the patient consisting of the previously reported p.Q289* nonsense (c.865C > T, exon 6) mutation, and a novel deletion (c.23_29del; p.Asp8Alafs10*) leading to a frameshift and a premature stop codon in exon 2. CARD9 protein expression was absent in peripheral blood mononuclear cells from the patient.
CONCLUSION: We describe here compound heterozygous loss-of-expression mutations in CARD9 leading to severe deep and destructive mucocutaneous phaeohyphomycosis due to C. cassiicola in a Colombian child.

PMID: 30264381 [PubMed - as supplied by publisher]

Combined linkage and association analysis identifies rare and low frequency variants for blood pressure at 1q31.

Eur J Hum Genet. 2018 Sep 27;:

Authors: Wang H, Nandakumar P, Tekola-Ayele F, Tayo BO, Ware EB, Gu CC, Lu Y, Yao J, Zhao W, Smith JA, Hellwege JN, Guo X, Edwards TL, Loos RJF, Arnett DK, Fornage M, Rotimi C, Kardia SLR, Cooper RS, Rao DC, Ehret G, Chakravarti A, Zhu X

Abstract
High blood pressure (BP) is a major risk factor for cardiovascular disease (CVD) and is more prevalent in African Americans as compared to other US groups. Although large, population-based genome-wide association studies (GWAS) have identified over 300 common polymorphisms modulating inter-individual BP variation, largely in European ancestry subjects, most of them do not localize to regions previously identified through family-based linkage studies. This discrepancy has remained unexplained despite the statistical power differences between current GWAS and prior linkage studies. To address this issue, we performed genome-wide linkage analysis of BP traits in African-American families from the Family Blood Pressure Program (FBPP) and genotyped on the Illumina Human Exome BeadChip v1.1. We identified a genomic region on chromosome 1q31 with LOD score 3.8 for pulse pressure (PP), a region we previously implicated in DBP studies of European ancestry families. Although no reported GWAS variants map to this region, combined linkage and association analysis of PP identified 81 rare and low frequency exonic variants accounting for the linkage evidence. Replication analysis in eight independent African ancestry cohorts (N = 16,968) supports this specific association with PP (P = 0.0509). Additional association and network analyses identified multiple potential candidate genes in this region expressed in multiple tissues and with a strong biological support for a role in BP. In conclusion, multiple genes and rare variants on 1q31 contribute to PP variation. Beyond producing new insights into PP, we demonstrate how family-based linkage and association studies can implicate specific rare and low frequency variants for complex traits.

PMID: 30262922 [PubMed - as supplied by publisher]

Exome sequencing of the TCL1 mouse model for CLL reveals genetic heterogeneity and dynamics during disease development.

Leukemia. 2018 Sep 27;:

Authors: Zaborsky N, Gassner FJ, Höpner JP, Schubert M, Hebenstreit D, Stark R, Asslaber D, Steiner M, Geisberger R, Greil R, Egle A

Abstract
The TCL1 mouse model is widely used to study pathophysiology, clonal evolution, and drug sensitivity or resistance of chronic lymphocytic leukemia (CLL). By performing whole exome sequencing, we present the genetic landscape of primary tumors from TCL1 mice and of TCL1 tumors serially transplanted into wild-type recipients to mimic clonal evolution. We show that similar to CLL patients, mutations in mice are frequently subclonal and heterogenous among different primary TCL1 mice. We further describe that this molecular heterogeneity mirrors heterogenous disease characteristics such as organ infiltration or CLL dependent T cell skewing. Similar to human CLL, we further observed the occurrence of novel mutations and structural variations during clonal evolution and found plasticity in the expansion of B cell receptor specific subclones. Thus, our results uncover that the genetic complexity, pathway dependence and clonal dynamics in mouse CLL are in relevant agreement to human CLL, and they are important to consider in future research using the TCL1 mouse for studying CLL.

PMID: 30262843 [PubMed - as supplied by publisher]

Detection of c.139G>A (D47N) mutation in GJA8 gene in an extended family with inheritance of autosomal dominant zonular cataract without pulverulent opacities by exome sequencing.

J Genet. 2018 Sep;97(4):879-885

Authors: Gunda P, Manne M, Adeel SS, Kondareddy RKR, Tirunilai P

Abstract
The aim of this studywas to identify the gene causing bilateral autosomal dominant zonular congenital cataract (ADZCC) without pulverulent opacities in an extended Muslim family by exome sequencing and subsequent analysis. An extended family of 37 members (14 affected and 23 unaffected) who belong to different nuclear families was screened for causative gene. Proband and her unaffected son were screened for causative variant by exome sequencing followed by Sanger sequencing of the proband's entire nuclear family. The rest of the members were further screened for variants detected, by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and tetra-primer amplification refractorymutation system-polymerase chain reaction (T-ARMS PCR). Review of exome sequencing data of the proband and her unaffected son for 40 known genes causing congenital nonsyndromic cataracts revealed two variants, namely c.139G>A (p.Asp47Asn; D47N) in the GJA8 gene and c.2036C>T in the FYCO1 gene to be potentially pathogenic. Further, validation of these two variants in the entire family showed cosegregation of c.139G>A variant in GJA8 with ADZCC without pulverulent opacities. Variation of c.2036C>T in FYCO1 was not associated with disease in the family. The mutation c.139G>A in the GJA8 gene detected in the present study was also previously reported in Caucasian and Chinese families but with different phenotypes, i.e. nuclear and nuclear pulverulent cataracts. Thus, the mutation c.139G>A in GJA8 appears to exhibit marked interfamilial phenotypic variability.

PMID: 30262699 [PubMed - in process]

A unique de novo gain-of-function variant in CAMK4 associated with intellectual disability and hyperkinetic movement disorder.

Cold Spring Harb Mol Case Stud. 2018 Sep 27;:

Authors: Zech M, Lam DD, Weber S, Berutti R, Poláková K, Havránková P, Fečíková A, Strom TM, Růžička E, Jech R, Winkelmann J

Abstract
Calcium/calmodulin-dependent protein kinases (CaMKs) are key mediators of calcium signaling and underpin neuronal health. Although widely studied, the contribution of CaMKs to Mendelian disease is rather enigmatic. Here, we describe an unusual neurodevelopmental phenotype, characterized by milestone delay, intellectual disability, autism, ataxia, and mixed hyperkinetic movement disorder including severe generalized dystonia, in a proband who remained etiologically undiagnosed despite exhaustive testing. We performed trio-whole-exome sequencing to identify a de novo essential splice-site variant (c.981+1G>A) in CAMK4, encoding CaMKIV. Through in silico evaluation and cDNA analyses, we demonstrated that c.981+1G>A alters CAMK4 pre-mRNA processing and results in a stable mRNA transcript containing a 77-nt out-of-frame deletion and a premature termination codon within the last exon. The expected protein, p.Lys303Serfs*28, exhibits selective loss of the C-terminal regulatory domain of CaMKIV and bears striking structural resemblance to previously reported synthetic mutants that confer constitutive CaMKIV activity. Biochemical studies in proband-derived cells confirmed an activating effect of c.981+1G>A and indicated that variant-induced excessive CaMKIV signaling is sensitive to pharmacological manipulation. Additionally, we found that variants predicted to cause selective depletion of CaMKIV`s regulatory domain are unobserved in diverse catalogs of human variation, thus revealing that c.981+1G>A is a unique molecular event. We propose that our proband`s phenotype is explainable by a dominant CAMK4 splice-disrupting mutation that acts through a gain-of-function mechanism. Our findings highlight the importance of CAMK4 in human neurodevelopment, provide a foundation for future clinical research of CAMK4, and suggest the CaMKIV signaling pathway as a potential drug target in neurological disease.

PMID: 30262571 [PubMed - as supplied by publisher]

Novel pathogenic variants in filamin C identified in pediatric restrictive cardiomyopathy.

Hum Mutat. 2018 Sep 27;:

Authors: Schubert J, Tariq M, Geddes G, Kindel S, Miller EM, Ware SM

Abstract
Restrictive cardiomyopathy (RCM) is a rare and distinct form of cardiomyopathy characterized by normal ventricular chamber dimensions, normal myocardial wall thickness, and preserved systolic function. The abnormal myocardium, however, demonstrates impaired relaxation. To date, dominant variants causing RCM have been reported in a small number of sarcomeric or cytoskeletal genes, but the genetic causes in a majority of cases remain unexplained especially in early childhood. Here, we describe two RCM families with childhood onset: one in a large family with a history of autosomal dominant RCM and the other a family with affected monozygotic, dichorionic/diamniotic twins. Exome sequencing found a pathogenic filamin C (FLNC) variant in each: p.Pro2298Leu which segregates with disease in the large autosomal dominant RCM family, and p.Tyr2563Cys in both affected twins. In vitro expression of both mutant proteins yielded aggregates of FLNC containing actin in C2C12 myoblast cells. Recently, a number of variants in FLNC have been described that cause hypertrophic, dilated, and restrictive cardiomyopathies. Our data presented here provide further evidence for the role of FLNC in pediatric RCM, and suggest the need to include FLNC in genetic testing of cardiomyopathy patients including those with early ages of onset. This article is protected by copyright. All rights reserved.

PMID: 30260051 [PubMed - as supplied by publisher]

Evidence GDF15 Plays a Role in Familial and Recurrent Hyperemesis Gravidarum.

Geburtshilfe Frauenheilkd. 2018 Sep;78(9):866-870

Authors: Fejzo MS, Arzy D, Tian R, MacGibbon KW, Mullin PM

Abstract
Introduction Hyperemesis gravidarum (HG), a pregnancy complication characterized by severe nausea and vomiting in pregnancy, occurs in up to 2% of pregnancies. It is associated with both maternal and fetal morbidity. HG is highly heritable and recurs in approximately 80% of women. In a recent genome-wide association study, it was shown that placentation, appetite, and the cachexia gene GDF15 are linked to HG. The purpose of this study was to explore whether GDF15 alleles linked to overexpression of GDF15 protein segregate with the condition in families, and whether the GDF15 risk allele is associated with recurrence of HG. Methods We analyzed GDF15 overexpression alleles for segregation with disease using exome-sequencing data from 5 HG families. We compared the allele frequency of the GDF15 risk allele, rs16982345, in patients who had recurrence of HG with its frequency in those who did not have recurrence. Results Single nucleotide polymorphisms (SNPs) linked to higher levels of GDF15 segregated with disease in HG families. The GDF15 risk allele, rs16982345, was associated with an 8-fold higher risk of recurrence of HG. Conclusion The findings of this study support the hypothesis that GDF15 is involved in the pathogenesis of both familial and recurrent cases of HG. The findings may be applicable when counseling women with a familial history of HG or recurrent HG. The GDF15-GFRAL brainstem-activated pathway was recently identified and therapies to treat conditions of abnormal appetite are under development. Based on our findings, patients carrying GDF15 variants associated with GDF15 overexpression should be included in future studies of GDF15-GFRAL-based therapeutics. If safe, this approach could reduce maternal and fetal morbidity.

PMID: 30258246 [PubMed]