Awareness of Fabry disease in cardiology: A gap to be filled

INTRODUCTION: In adults, unexplained left ventricular hypertrophy is usually due to sarcomeric hypertrophic cardiomyopathy (HCM). Fabry disease (FD) is rare but may mimic sarcomeric HCM, and has an adverse prognosis in the absence of specific treatment. We aimed to assess cardiologists' awareness of FD based on data from the Portuguese Registry of Hypertrophic Cardiomyopathy.

METHODS: A total of 811 index patients, aged 55 ± 16 years, 486 (59.9%) male, were included. Three groups were characterized: A - 128 patients, 74 (57.8%) male, with pathogenic or likely pathogenic mutation(s) in sarcomeric genes; B - 234 patients, 146 (62.4%) male, with negative genetic testing; and C - 449 patients, 266 (59.2%) male, no genetic testing performed. The groups were compared in terms of whether FD was excluded in the registry. Potential red flags for FD were also analyzed and compared between groups.

RESULTS: Patients in group A were younger and more frequently had familial HCM (A - 53.9% vs. B - 20.1% vs. C - 18.3%; p <0.001). FD was recorded as excluded in 217 (26.8%), similar in all groups; GLA gene testing was performed in only 50/217 patients (A - 48.6%, B - 25.7%, p = 0.019; C - 13.4%, p = 0.036 for B vs. C), mostly in women (p <0.001) in groups B and C. Alpha-galactosidase A (α-Gal A) activity was assessed in 39/217 (18%) patients, with no difference between groups, but more often in men (p = 0.005). Among patients with potential red flags for FD, only 46.7% underwent specific tests (GLA gene testing and/or α-Gal A activity). When GLA genotyping was performed no mutations were identified.

CONCLUSIONS: There is a need to improve cardiologists' alertness for the identification of FD among the Portuguese HCM population.