講演情報
[O19-1]心室中部閉塞型肥大型心筋症を呈したファブリー病患者の臨床的特徴
○稲垣 夏子1, 林 丈晴2, 武井 康悦1, 鈴木 慎二3 (1.東京医科大学 循環器内科学分野, 2.東海大学 医学部 医学科 基礎医学系 生体構造機能学, 3.東京医科大学 小児科・思春期科学分野)
Fabry disease (FD) is an X-linked lysosomal storage disease caused by mutations in GLA, encoding α-galactosidase A (GLA). The loss or reduced activity of GLA leads to multiple organ damage resulting in intracellular accumulation of globotriaosylceramide in various organs, including heart, kidney and nervous system. Pathological changes in the heart usually result in concentric left ventricular hypertrophy. Hypertrophic cardiomyopathy (HCM) is an intractable disease characterized by unexplained left ventricular hypertrophy and diastolic dysfunction, typically with asymmetric left ventricular hypertrophy. We performed a causative gene analysis for patients with a rare subtype of HCM, HCM with midventricular obstruction (HCM-MVO), and identified four patients with different pathological variants in GLA, which were clinically confirmed as FD. All the four FD patients with the rare HCM-MVO morphology were female, three of them with the classical form and one with the cardiac subtype. Three cases in whom lymphocyte Lyso-Gb3 was measured showed a marked decrease in Lyso-Gb3 after starting the Enzyme replacement therapy (ERT). However, even after ERT, myocardial involvement worsened in the long term, and two patients experienced fatal arrhythmias. Therefore, it was difficult to determine the efficacy of myocardial involvement in FD by evaluation using the lymphocyte-based Lyso-Gb3 assay system. In addition, none of the female patients had renal dysfunction, indicating that the pattern of organ damage was different from that in the previously reported male patients.