{"doi":"10.3389/fcvm.2021.766339","title":"South Asian-Specific MYBPC3Δ25bp Deletion Carriers Display Hypercontraction and Impaired Diastolic Function Under Exercise Stress","abstract":"Background: A 25-base pair (25bp) intronic deletion in the MYBPC3 gene enriched in South Asians (SAs) is a risk allele for late-onset left ventricular (LV) dysfunction, hypertrophy, and heart failure (HF) with several forms of cardiomyopathy. However, the effect of this variant on exercise parameters has not been evaluated. Methods: As a pilot study, 10 asymptomatic SA carriers of the MYBPC3 Δ25bp variant (52.9 ± 2.14 years) and 10 age- and gender-matched non-carriers (NCs) (50.1 ± 2.7 years) were evaluated at baseline and under exercise stress conditions using bicycle exercise echocardiography and continuous cardiac monitoring. Results: Baseline echocardiography parameters were not different between the two groups. However, in response to exercise stress, the carriers of Δ25bp had significantly higher LV ejection fraction (%) (CI: 4.57 ± 1.93; p < 0.0001), LV outflow tract peak velocity (m/s) (CI: 0.19 ± 0.07; p < 0.0001), and higher aortic valve (AV) peak velocity (m/s) (CI: 0.103 ± 0.08; p = 0.01) in comparison to NCs, and E/A ratio, a marker of diastolic compliance, was significantly lower in Δ25bp carriers (CI: 0.107 ± 0.102; p = 0.038). Interestingly, LV end-diastolic diameter (LVID dia ) was augmented in NCs in response to stress, while it did not increase in Δ25bp carriers (CI: 0.239 ± 0.125; p = 0.0002). Further, stress-induced right ventricular systolic excursion velocity s' (m/s), as a marker of right ventricle function, increased similarly in both groups, but tricuspid annular plane systolic excursion increased more in carriers (slope: 0.008; p = 0.0001), suggesting right ventricle functional differences between the two groups. Conclusions: These data support that MYBPC3 Δ25bp is associated with LV hypercontraction under stress conditions with evidence of diastolic impairment.","journal":"Frontiers in Cardiovascular Medicine","year":2021,"id":196715,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":6,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9104,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":769467,"name":"Robert Sibilia","orcid":"0000-0003-3995-5966","position":1,"is_corresponding":false},{"id":769937,"name":"Saavia Girgla","orcid":null,"position":2,"is_corresponding":false},{"id":769468,"name":"Shiv Kumar Viswanathan","orcid":"0000-0002-3825-3121","position":3,"is_corresponding":false},{"id":463597,"name":"Megan J. Puckelwartz","orcid":"0000-0002-0455-2983","position":4,"is_corresponding":false},{"id":769938,"name":"Kiranpal S. Sangha","orcid":null,"position":5,"is_corresponding":false},{"id":706356,"name":"Rohit Singh","orcid":"0000-0002-7282-2025","position":6,"is_corresponding":false},{"id":769939,"name":"Mashhood Kakroo","orcid":null,"position":7,"is_corresponding":false},{"id":481542,"name":"Roman Jandarov","orcid":"0000-0003-2145-045X","position":8,"is_corresponding":false},{"id":769469,"name":"David M. Harris","orcid":"0000-0002-3272-6151","position":9,"is_corresponding":false},{"id":369003,"name":"Jack Rubinstein","orcid":"0000-0002-8811-1551","position":10,"is_corresponding":false},{"id":32896,"name":"Richard C. Becker","orcid":"0000-0002-9878-7707","position":11,"is_corresponding":false},{"id":297686,"name":"Elizabeth M. McNally","orcid":"0000-0002-1221-719X","position":12,"is_corresponding":false},{"id":274731,"name":"Sakthivel Sadayappan","orcid":"0000-0003-2006-7678","position":13,"is_corresponding":false},{"id":769466,"name":"Sholeh Bazrafshan","orcid":"0000-0003-2071-5153","position":0,"is_corresponding":true}],"reference_count":59,"raw_metadata":null,"created_at":"2026-07-18T23:50:15.704473Z","pmid":"35004883","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}