title: Genetic and clinical profile of Indian patients of idiopathic restrictive cardiomyopathy with and without hypertrophy.
abstract: Both idiopathic restrictive cardiomyopathy (IRCM) and hypertrophic cardiomyopathy (HCM) are part of the same disease spectrum and are due to sarcomeric gene mutations. A patient with restrictive physiology without left ventricular hypertrophy (LVH) would be diagnosed as IRCM, while one with LVH would be diagnosed as HCM with restrictive physiology. We studied a group of patients with restrictive physiology for mutations in beta-myosin heavy chain (MYH7) and troponin I (TNNI3) gene. Consecutive probands in the HCM and IRCM cohort over a 4-year period were considered for this study. These included 10 IRCM and 102 HCM patients. All were Asian Indians. Among the 17 patients who had restrictive physiology 10 were IRCM patients and seven were HCM patients. Of the HCM patients, seven (6.9%) had restrictive physiology. Mean age of these 17 patients was 40.1 +/- 19.2 years (range: 15-67 ), six (35.3%) were males. Maximal left ventricular wall thickness of the seven HCM probands was 20.7 +/- 5.2 mm (range: 16-31), while it was normal in the IRCM probands. Ten probands (58.8%) were in NYHA class III or IV. Seven patients (41.2%) had atrial fibrillation. All the probands were screened for mutations in selected exons of MYH7 and TNNI3 genes. One IRCM patient was found to have p.Arg721Lys mutation in the MYH7 gene. She died due to progressive congestive cardiac failure at the age of 47 years. One HCM proband with a maximal left ventricular wall thickness of 17 mm had p.Arg192His mutation in the TNNI3 gene. She had features consistent with restrictive physiology. Her father and sister had died of restrictive cardiomyopathy. IRCM and HCM with restrictive physiology, both are part of the clinical expression of MYH7 and TNNI3 mutations and lead to worse clinical onset and progression of the disease.
authors.affiliation: Department of Experimental Medicine and Biotechnology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Taranjit Singh
authors.initials: TS
authors.lastname: Rai
authors.forename: Shamim
authors.initials: S
authors.lastname: Ahmad
authors.forename: Tarunveer Singh
authors.initials: TS
authors.lastname: Ahluwalia
authors.forename: Monica
authors.initials: M
authors.lastname: Ahuja
authors.forename: Ajay
authors.initials: A
authors.lastname: Bahl
authors.forename: Uma Nahar
authors.initials: UN
authors.lastname: Saikia
authors.forename: Balvinder
authors.initials: B
authors.lastname: Singh
authors.forename: Kewal K
authors.initials: KK
authors.lastname: Talwar
authors.forename: Madhu
authors.initials: M
authors.lastname: Khullar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019943:Amino Acid Substitution / Q000235:genetics; D044466:Asian People / Q000235:genetics*; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology; D002313:Cardiomyopathy, Restrictive / Q000150:complications* / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology; D004252:DNA Mutational Analysis; D005190:Family; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D014463:Ultrasonography; D055815:Young Adult