title: Sarcomere protein gene mutations in patients with apical hypertrophic cardiomyopathy.
abstract: BACKGROUND
  Apical hypertrophic cardiomyopathy (HCM) is a unique form of HCM with left ventricular hypertrophy confined to the cardiac apex. The purpose of our study was to report genetic findings in a large series of unrelated patients with apical HCM and compare them with a nonapical HCM cohort.
  
  
  RESULTS
  Overall, 429 patients with HCM underwent genetic testing. The panel included 8 sarcomere protein genes and 3 other genes (GLA, PRKAG2, and LAMP2). Sixty-one patients were diagnosed with apical HCM. A positive genotype was found in 8 patients with apical HCM. The genotype-positive and genotype-negative patients had similar maximal wall thicknesses (17.5 ± 3.5 mm versus 17.6 ± 3.3 mm, P = 0.71) and similar frequency of HCM-related events (2/8; 25% versus 13/53; 25%; P = 0.98). Thirteen percent with apical HCM and 40% with nonapical HCM had a positive genotype (P<0.001) most often involving the MYBPC3 and MYH7 genes.
  
  
  CONCLUSIONS
  In apical HCM, a positive genotype was found less frequently than in nonapical HCM, and it was most often involving MYBPC3 and MYH7 genes. Only 13% of patients with apical HCM were found to be genotype positive, indicating that genome-wide association studies and gene expression profiling are needed for better understanding of the genetic background of the disease. There was no significant genotype-phenotype correlation in our cohort with apical HCM.
authors.affiliation: Division of Cardiology, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada. christiane.gruner@gmx.ch
authors.forename: Christiane
authors.initials: C
authors.lastname: Gruner
authors.forename: Melanie
authors.initials: M
authors.lastname: Care
authors.forename: Katherine
authors.initials: K
authors.lastname: Siminovitch
authors.forename: Gil
authors.initials: G
authors.lastname: Moravsky
authors.forename: E Douglas
authors.initials: ED
authors.lastname: Wigle
authors.forename: Anna
authors.initials: A
authors.lastname: Woo
authors.forename: Harry
authors.initials: H
authors.lastname: Rakowski
mesh_terms: D000293:Adolescent; D000328:Adult; D002312:Cardiomyopathy, Hypertrophic / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000235:genetics*; D009154:Mutation; D012518:Sarcomeres / Q000235:genetics* / Q000378:metabolism*
chemical_list: D009124:Muscle Proteins