Comprehensive clinical evaluation of a large Spanish family with Anderson-Fabry disease, novel GLA mutation and severe cardiac phenotype

Ventricular arrhythmias and primary prevention of sudden cardiac death in Anderson-Fabry disease

The Anderson-Fabry disease (AFD) is a X-linked lysosomal storage disorder due to the deficiency in the α-galactosidase A enzyme. Cardiovascular mortality is a major cause of death in patients with AFD and sudden cardiac death (SCD) is one of the main causes of death. The storage of glycosphingolipid along with ionic channel impairment, inflammation and fibrosis are involved in the arrhythmogenesis. Some risk factors have been associated with ventricular tachycardia (VT)/ventricular fibrillation (VF) and SCD. Left ventricular hypertrophy (LVH), cardiac fibrosis, non-sustained VTs seem to be the most important. Older age and male gender might be associated with higher risk of ventricular arrhythmias and SCD. Currently, the implantable cardioverter-defibrillator (ICD) is recommended in patients with AFD who have survived a cardiac arrest secondary to VT/VF or who experienced sustained VT causing syncope or hemodynamic compromise, and have a life expectancy >1 year. ICD implantation is also recommended in patients considered to be at high risk (e.g., patients with severe LVH or fibrosis). The present review sought to summarize the risk of ventricular arrythmias in AFD, the indications for ICD, focusing on pathophysiology and analyzing the role of possible predictors of arrhythmias in preventing SCD, especially as primary prevention.

Clinical evaluation, accurate diagnosis and treatment of four pedigrees with Fabry's disease

OBJECTIVE

This article analyzes the data of four families with mutations of the GLA (galactosidase) gene with a special focus on the clinical presentation, diagnosis, and interdisciplinary clinical management of Fabry disease (FD) and enzyme replacement therapy (ERT) treatment, and has the aim to assess more accurate prevention and treatment strategy.

METHODS

The MSSI (Mainz Severity Score Index) scale was used to evaluate the clinical data of five children diagnosed in our hospital, and the genotypes of all the patients with FD were collected. Two of the male children started ERT. We summarize the clinical effect and the evaluation of globotriaosylsphingosine (Lyso-GL-3) before and after treatment.

RESULTS

Five children were confirmed as having FD using the family histories, clinical manifestations, α-galactosidase A (a-Gal A) activity, and genetic test results. Two children used agalsidase α every 2 weeks regularly, after ERT. Their clinical symptoms improved, their pain intensity was significantly relieved, and upon re-examination their Lyso-GL-3 decreased conspicuously and no serious adverse reactions occurred. We report for the first time four families with children with FD. The youngest child was only 1 year old. The four families included one girl which is rare in X-linked lysosomal storage diseases.

CONCLUSION

The clinical phenotype of FD in childhood is nonspecific, and the misdiagnosis rate is high. Most children with FD have a delayed diagnosis, and their organs are often seriously damaged in adulthood. Pediatricians must improve their diagnosis and treatment awareness, screen high-risk groups, and emphasize multidisciplinary cooperation and holistic lifestyle management after diagnosis. The diagnosis of the proband is also conducive to the mining of other cases of FD families and has important guiding significance for prenatal diagnosis.

Ventricular arrhythmia and sudden cardiac death in Fabry disease: a systematic review of risk factors in clinical practice

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by deficiency of α-galactosidase A enzyme. Cardiovascular (CV) disease is a common cause of mortality in FD, in particular as a result of heart failure and arrhythmia, with a significant proportion of events categorized as sudden. There are no clear models for risk prediction in FD. This systematic review aims to identify the risk factors for ventricular arrhythmia (VA) and sudden cardiac deaths (SCD) in FD. A systematic search was performed following PRISMA guidelines of EMBASE, Medline, PubMed, Web of Science, and Cochrane from inception to August 2016, focusing on identification of risk factors for the development of VA or SCD. Thirteen studies were included in the review (n = 4185 patients) from 1189 articles, with follow-up of 1.2-10 years. Weighted average age was 37.6 years, and 50% were male. Death from any cause was reported in 8.3%. Of these, 75% was due to CV problems, with the majority being SCD events (62% of reported deaths). Ventricular tachycardia was reported in 7 studies, with an average prevalence of 15.3%. Risk factors associated with SCD events were age, male gender, left ventricular hypertrophy, late gadolinium enhancement on CV magnetic resonance imaging, and non-sustained ventricular tachycardia. Although a multi-system disease, FD is a predominantly cardiac disease from a mortality perspective, with death mainly from SCD events. Limited evidence highlights the importance of clinical and imaging risk factors that could contribute to improved decision-making in the management of FD.

COMPUTER ASSISTED RETINAL VESSEL TORTUOSITY EVALUATION IN NOVEL MUTATION FABRY DISEASE: Towards New Prognostic Markers

PURPOSE

Fabry disease is a rare lysosomal storage disorder with systemic involvement. The authors report on a large Fabry family with GLA p.M187R mutation and exhaustive ophthalmologic assessment.

METHODS

Comprehensive systemic evaluation and genetic diagnosis were performed. Ophthalmologic evaluation included intraocular pressure/visual acuity measurement, refractometry, slit lamp examination, retinography, and optical coherence tomography. Three parameters quantified retinal vessel tortuosity: sum of angle metrics, product of angle distance, and triangular index. Calculations were semiautomatized using dedicated software.

RESULTS

Ten individuals (2 males and 8 females) were described. Seventy-five percent had retinal vessel tortuosity. One hundred percent had cornea verticillata. Perimacular vessels were predominantly involved. The correlation between the right and left eye tortuosity measurements was very tight. A significant correlation between retinal vessel tortuosity and systemic severity measured by general Mainz Severity Score Index (MSSI), renal MSSI, and neurological MSSI but no cardiac MSSI was observed. Right sum of angle metrics value was an independent statistical predictor of the general-MSSI score in presence of age.

CONCLUSION

p.M187R mutation causes a severe systemic and ophthalmologic phenotype, in both male and female patients. Semiautomatic assessment of retinal vessel tortuosity is an objective and reproducible tool. All three parameters of tortuosity are closely associated with Fabry severity scores. Studies of larger series are being awaited to establish the role of retinal vessel tortuosity as a noninvasive marker of disease progression.