Fabry Disease

Abstract

A 41-year-old male visited our hospital with proteinuria and hearing loss. The patient is Japanese, had never experienced pain attacks in the extremities, and sweats normally. He did not present with chest pains and palpitations and often had diarrhea without abdominal pain. Proteinuria was diagnosed when he was 25 years old, and he was then diagnosed with chronic nephritis. At 30 years of age, he experienced recurrent sudden-onset deafness, sometimes with tinnitus. He had hypertension, hypercholesterolemia, and hyperuricemia. His electrocardiogram revealed arrhythmia, and he had a panic disorder. He gave up smoking when he was 30 years old. His mother had cardiac involvement with Fabry disease but no history of kidney diseases. She also had a c.465 T > A (amino acid: D155E) heterozygous mutation in α-galactosidase A of white blood cells. Physical examination revealed his body mass index was 22.5 kg/m² and had regular heartbeats, but no hepatosplenomegaly, no angiokeratoma, no rash, and no any neurological sign. In his blood counts, there were normal white blood cells and platelet but no anemia. His serum creatinine 0.97 mg/dL (normal; 0.65–1.07), estimated glomerular filtration rate (eGFR) 69 mL/min/1.73 m² (normal; >90) and cystatin C 0.90 mg/L (normal; 0.63–0.95), LDL-cholesterol 98 mg/dL (65–139), and triglyceride 188 mg/dL (normal; 40–149) were almost normal, but brain natriuretic peptide 55.3 pg/mL(normal; <18.5) was slightly elevated. He exhibited proteinuria (3+) and quantitative urine protein/creatinine ratio 3.8 g/g Cr (normal; <0.3) but not hematuria. Serum α-galactosidase A activity 2.82 nmol/hr/mg protein in his white blood cells was extremely low (normal control: 155.85–222.59). Thin-layer chromatography of his urinary lipids indicated globotriaosylceramide (Gb3) positive (Fig. 4.1). Gene analysis identified c.465 T > A (amino acid: D155E) hemizygous mutation in α-galactosidase A of his white blood cells.