Early recognition of PRKAG2 syndrome in an adolescent with a hypertrophic cardiomyopathy phenotype and ventricular pre-excitation: a case report
- 1Heart Center, The First Hospital of Tsinghua University, School of Clinical Medicine, Tsinghua Medicine, Tsinghua University, Beijing, China
Abstract
Background: PRKAG2 syndrome is a rare glycogen-storage cardiomyopathy that can mimic sarcomeric hypertrophic cardiomyopathy (HCM). The diagnostic clue is not left ventricular hypertrophy alone, but the combination of hypertrophy with ventricular pre-excitation and conduction-system abnormalities. This pattern is clinically important because PRKAG2 syndrome differs from sarcomeric HCM in disease progression, arrhythmic risk, and long-term management.
Case presentation: A 12-year-old boy presented with recurrent exertional chest tightness. Twelve-lead electrocardiography showed ventricular pre-excitation, and echocardiography demonstrated asymmetric non-obstructive left ventricular hypertrophy. An external Holter report recorded sinus bradycardia and nocturnal pauses. Genetic testing identified a heterozygous PRKAG2 variant, NM_016203:c.1423A>G (p.Lys475Glu), classified as likely pathogenic. The available report from a clinically indicated invasive electrophysiological procedure documented persistent pre-excitation and localized the earliest antegrade ventricular activation to the right midseptal para-Hisian region. Catheter ablation was deferred because no tachyarrhythmia had been documented and ablation near the His bundle carried a substantial risk of atrioventricular block. During approximately 2 years of follow-up, the patient remained clinically stable, with persistent hypertrophy and no major arrhythmic or conduction events.
Conclusions: In adolescents with otherwise unexplained ventricular hypertrophy, ventricular pre-excitation should prompt consideration of PRKAG2 syndrome and other HCM phenocopies, even without a positive family history. Recognition of this combined structural and electrical phenotype may facilitate earlier genetic diagnosis and guide long-term rhythm surveillance. The mechanism of pre-excitation should be described only to the extent supported by the available electrocardiographic and procedural documentation.
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BibTeX
@article{hou2026early,
title = {{Early recognition of PRKAG2 syndrome in an adolescent with a hypertrophic cardiomyopathy phenotype and ventricular pre-excitation: a case report}},
author = {Zonghui Hou and Xuechen Liu and Mengqi Zhao and Junxiang Pan and Feiyang Wang and Chunbo Wang and Lianyi Wang},
journal = {BMC Cardiovascular Disorders},
year = {2026},
month = aug,
doi = {10.1186/s12872-026-06433-0},
url = {https://doi.org/10.1186/s12872-026-06433-0},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Early recognition of PRKAG2 syndrome in an adolescent with a hypertrophic cardiomyopathy phenotype and ventricular pre-excitation: a case report
AU - Zonghui Hou
AU - Xuechen Liu
AU - Mengqi Zhao
AU - Junxiang Pan
AU - Feiyang Wang
AU - Chunbo Wang
AU - Lianyi Wang
PY - 2026
DA - 2026/08/01
JO - BMC Cardiovascular Disorders
DO - 10.1186/s12872-026-06433-0
UR - https://doi.org/10.1186/s12872-026-06433-0
AB - Background: PRKAG2 syndrome is a rare glycogen-storage cardiomyopathy that can mimic sarcomeric hypertrophic cardiomyopathy (HCM). The diagnostic clue is not left ventricular hypertrophy alone, but the combination of hypertrophy with ventricular pre-excitation and conduction-system abnormalities. This pattern is clinically important because PRKAG2 syndrome differs from sarcomeric HCM in disease progression, arrhythmic risk, and long-term management. Case presentation: A 12-year-old boy presented with recurrent exertional chest tightness. Twelve-lead electrocardiography showed ventricular pre-excitation, and echocardiography demonstrated asymmetric non-obstructive left ventricular hypertrophy. An external Holter report recorded sinus bradycardia and nocturnal pauses. Genetic testing identified a heterozygous PRKAG2 variant, NM_016203:c.1423A>G (p.Lys475Glu), classified as likely pathogenic. The available report from a clinically indicated invasive electrophysiological procedure documented persistent pre-excitation and localized the earliest antegrade ventricular activation to the right midseptal para-Hisian region. Catheter ablation was deferred because no tachyarrhythmia had been documented and ablation near the His bundle carried a substantial risk of atrioventricular block. During approximately 2 years of follow-up, the patient remained clinically stable, with persistent hypertrophy and no major arrhythmic or conduction events. Conclusions: In adolescents with otherwise unexplained ventricular hypertrophy, ventricular pre-excitation should prompt consideration of PRKAG2 syndrome and other HCM phenocopies, even without a positive family history. Recognition of this combined structural and electrical phenotype may facilitate earlier genetic diagnosis and guide long-term rhythm surveillance. The mechanism of pre-excitation should be described only to the extent supported by the available electrocardiographic and procedural documentation.
SN - 1471-2261
ER -