ABC | Volume 113, Nº1, July 2019

Original Article Chaves-Markman et al A novel mutation in Fabry disease Arq Bras Cardiol. 2019; 113(1):77-84 Table 1 – Clinical characteristics and complementary test results of patients HCM (n=56) GLA mutation (n = 4) p-value Age (years) 42.3 ± 17.0 58.5 ± 15.2 0.11 Gender (female) 59.9% 75% 0.53 EF (%) † 67.6 ± 8.6 65.0 ± 4.2 0.43 Cardiac symptoms Dyspnea 8% 25% 0.80 Precordial pain 5% - Syncope 17.5% 50% Palpitation 5% - Dizziness 7% - Predominance of LVH † Apical 5.56% 25% 0.38 Concentric 25% 25% AS 61.1% 50% AM 0.05% - PMH 2.78% - MVT (mm) † 19.1 ± 6.4 18.7 ± 0.9 0.98 Fibrosis on MRI (%) 11.0 ± 13.9 12.0 ± 11.6 0.82 ECG alteration LVO 38.5% 100% 0.83 LAE 10.3% - AVR 28.6% - LBBB 10.3% 25% AVB 5.1% 50% QRSFrag 20.5% - HCM: hypertrophic cardiomyopathy; EF: ejection fraction; LVH: left ventricular hypertrophy; AS: Asymmetric septal; AM: anteromedial; PMH: papillary muscle hypertrophy; MVT: maximum ventricular thickness; MRI: magnet resonance imaging; ECG: electrocardiogram; LVO: left ventricular outflow tract; LAE: left atrium enlargement; AVR: abnormal ventricular repolarization; LBBB: left bundle branch block; AVB: atrioventricular block; QRSFrag: QRS fragmentation. † measurement via transthoracic echocardiography (TTE). Paired student’s t -test was used to compare the baseline characteristics of both HCM and GLA mutation groups, and Pearson’s chi-square test was used to identify any associations between the clinical variables. Ethical standards The study was approved by the Institutional Ethics Committee and was carried out according to Resolution 196/96 of the Brazilian National Health Council, which deals with the guidelines and standards for research involving human subjects. The investigation was also conducted in accordance with the Declaration of Helsinki. Informed consent was obtained from all patients before inclusion in this study. Results We included 60 patients with an echocardiographic diagnosis of HCM that underwent molecular tests for FD. Their age ranged from 12 to 85 years (mean 42.3 ± 17), and 60% (n = 36) were women. Four patients, three of which were women, had GLA gene mutations, corresponding to 6.7% of our sample. Syncope and dyspnea were the most frequent cardiac symptoms in all patients. Asymmetric septal hypertrophic cardiomyopathy was the most frequent type in patients without GLA mutations (61.5%) and in the GLA mutation group (50%). EF was similar in both groups. The most common electrocardiographic patterns of all patients were left ventricular hypertrophy (37.9%), atrioventricular block (13.8%) and left bundle branch block (10.3%). The clinical and epidemiological baseline characteristics of our sample are shown in Table 1. Three mutations with heterozygote variants were found: c.967C>A (p.Pro323Thr), which is a novel mutation not yet described in literature (Figure 1); c.937G>T (p.Asp313Tyr); and c.352C>T (p.Arg118Cys). One homozygous variant was also found: c.352C>T (p.Arg118Cys). Five male patients underwent molecular analysis due to low α -Gal A enzyme activity; however, none of them had GLA gene mutations. The clinical and epidemiological characteristics of the patients with GLA gene mutations are described in Table 2. Discussion In our sample of 60 patients with HCM, we determined through molecular tests that the prevalence of GLA mutation was 6.7%. Additionally, we found a new mutation in the GLA gene. Enzyme replacement was started in one patient with GLA mutation. 79