Biopsy-proven cardiomyopathy in heterozygous Fabry's disease

X Chromosome Inactivation in Carriers of Fabry Disease: Review and Meta-Analysis

Anderson-Fabry disease is an X-linked inborn error of glycosphingolipid catabolism caused by a deficiency of α-galactosidase A. The incidence ranges between 1: 40,000 and 1:117,000 of live male births. In Italy, an estimate of incidence is available only for the north-western Italy, where it is of approximately 1:4000. Clinical symptoms include angiokeratomas, corneal dystrophy, and neurological, cardiac and kidney involvement. The prevalence of symptomatic female carriers is about 70%, and in some cases, they can exhibit a severe phenotype. Previous studies suggest a correlation between skewed X chromosome inactivation and symptoms in carriers of X-linked disease, including Fabry disease. In this review, we briefly summarize the disease, focusing on the clinical symptoms of carriers and analysis of the studies so far published in regards to X chromosome inactivation pattern, and manifesting Fabry carriers. Out of 151 records identified, only five reported the correlation between the analysis of XCI in leukocytes and the related phenotype in Fabry carriers, in particular evaluating the Mainz Severity Score Index or cardiac involvement. The meta-analysis did not show any correlation between MSSI or cardiac involvement and skewed XCI, likely because the analysis of XCI in leukocytes is not useful for predicting the phenotype in Fabry carriers.

Fabry Disease Presenting with Hypertrophic Cardiomyopathy and Tricuspid Regurgitation

A 71-year-old female who was diagnosed with nonobstructive hypertrophic cardiomyopathy since 1999 presented with dyspnea and severe edema on both legs. For the management of her symptom, cardiac surgery including tricuspid annuloplasty, Maze operation and right atrial reduction plasty was performed. During follow-up after cardiac surgery, a plasma α-galactosidase activity was checked for the screening of Fabry disease and the result was around lower normal limit. DNA analysis was implemented for confirmation and it revealed a heterozygote α-galactosidase mutation at exon 6 [c.901C>T (p.Arg301Ter)]. This case suggests that Fabry disease might be easily undetected, and clinical suspicion is critical.

Onset and progression of the Anderson-Fabry disease related cardiomyopathy

BACKGROUND

Cardiac involvement is responsible for substantial morbidity and mortality in Anderson-Fabry disease (AFD). We sought to document its onset and progression in a population of male and female AFD patients.

METHODS

We performed a cross sectional echocardiographic study of a cohort of 177 male and female AFD patients with subsequent longitudinal follow-up of 76 patients (38 males and 38 females; mean follow-up 4.5 years) who did not receive enzyme replacement therapy.

RESULTS

In this population, aged 3.3 to 70.8 years, a strong correlation between age and left ventricular mass indexed (LVMi, g/m(2.7)) was found in both males and females (P<0.0001 for both). At the initial examination 48.6% of the male patients and 36.4% of the female patients were classified as having left ventricular hypertrophy (LVH). The cumulative prevalence of LVH peaked at age 40 years in males and 60 years in females. In patients with longitudinal follow-up, LVMi increased by 4.07+/-1.03 g/m(2.7) per year in males and by 2.31+/-0.81 g/m(2.7) in females (P<0.01, Wilcoxon rank sum). In patients with LVH at baseline, the median progression rate was 5.52 g/m(2.7) per year in males and by 1.80 g/m(2.7) in females (P=0.12).

CONCLUSION

AFD is associated with high prevalence of LVH in both genders. However, the age of onset is delayed in females and progression rate slower.

Ventricular tachycardias and dilated cardiomyopathy caused by Fabry disease

Women with Fabry disease are considered to have a good prognosis. Here we report the clinical history of a female patient with severe Fabry disease before and after referral to our hospital. She was diagnosed to have a cardiac variant of Fabry disease since a left ventricular endomyocardial biopsy revealed specific features of this disease and that cardiac involvement was the sole manifestation. She developed sustained ventricular tachycardia and dilated cardiomyopathy requiring oral administration of amiodarone and a cardiac defibrillator implant.

An approach to endomyocardial biopsy interpretation

The endomyocardial biopsy (EMB) remains the gold standard mode of investigation for diagnosing many primary and secondary cardiac conditions. Through a percutaneous and transvenous route, tissue fragments are generally procured from the right ventricular septum, with very few complications. Widespread use of EMB followed the development of heart transplantation as a means to follow allograft rejection. It has since been useful in helping to diagnose conditions affecting the heart, including cardiomyopathies, myocarditis, infiltrative lesions, arrhythmias, and drug toxicities. The procedure has also been used as a research tool to investigate the natural history of disease and the cardiotoxicity of new medications. This review presents an approach to the evaluation of the EMB, which is particularly directed towards those who may be asked to interpret such biopsies, but are not dedicated cardiovascular pathologists. Through a systematic evaluation of the endocardium, myocardium, interstitium, and intramural vessels, in the context of a complete clinical history, enough information can be deduced to diagnose or exclude specific conditions of clinical value.

Chloroquine cardiotoxicity: clinicopathologic features in three patients and comparison with three patients with Fabry disease

BACKGROUND

Microscopic features of chloroquine cardiotoxicity are similar to those of Fabry disease. The purpose of the study was to compare clinicopathologic findings in both disorders.

METHODS

Patients with a diagnosis of chloroquine cardiotoxicity or Fabry disease were identified who had undergone endomyocardial biopsy or autopsy at Mayo Clinic Rochester (1976-2000). Clinical information was collected from medical records and letters from referring physicians. Light and electron microscopy were performed in all cases.

RESULTS

Three patients (two women, one man) with chloroquine cardiotoxicity ranged in age from 53 to 73 years. Chloroquine was given for rheumatoid arthritis in two and systemic lupus erythematosus in one. Three patients (two men, one woman) with Fabry disease ranged in age from 58 to 76 years. Two had angiokeratomas, but only one had a previous diagnosis of Fabry disease. All six patients presented with dyspnea. Light microscopy from all six revealed myocyte enlargement due to perinuclear vacuolization. By transmission electron microscopy, all six showed abundant myelinoid figures within involved myocytes. Curvilinear bodies were observed in two patients with chloroquine cardiotoxicity and in none with Fabry disease.

CONCLUSIONS

Patients with cardiac dysfunction due to chloroquine cardiotoxicity or Fabry disease have similar ages, presenting clinical symptoms, cardiac light microscopy and sarcoplasmic myelinoid bodies ultrastructurally. Patients with Fabry disease may not have a personal or family history of the disease. Similarly, a history of chloroquine usage may not be known to the pathologist. In these settings, the presence of curvilinear bodies ultrastructurally is useful for the diagnosis of chloroquine cardiotoxicity.

Anderson-Fabry disease: clinical manifestations of disease in female heterozygotes

Anderson-Fabry disease is a rare, X-chromosomal lipid storage disorder caused by a deficiency of lysosomal alpha-galactosidase A. Clinical manifestations of Anderson-Fabry disease include excruciating pain in the extremities (acroparaesthesia), skin vessel ectasia (angiokeratoma), corneal and lenticular opacity, cardiovascular disease, stroke and renal failure, only renal failure being a frequent cause of death. Heterozygote female carriers have often been reported as being asymptomatic or having an attenuated form of the disease. To evaluate the spectrum of clinical signs in heterozygotes, a comprehensive clinical examination was performed on 20 carriers of Anderson-Fabry disease. This revealed that, in addition to the skin manifestation, various other clinical manifestations of the disease are present, including acroparaesthesia, kidney dysfunction, cerebrovascular disease, and gastrointestinal and heart problems. It therefore appears that Anderson-Fabry disease affects both hemizygotes and heterozyotes and therefore should be considered to be an X-linked dominant disease.