Clinical and molecular characterization of an extended family with fabry disease

Abstract

Objective: To characterize clinical manifestations, biochemical changes, mutation of alpha-Galactosidase (□-Gal A) gene A (GLA), and functional capability of mutant protein. Material and Method: Seventeen subjects from a family with a newly diagnosed patient with Fabry disease were enrolled in the present study. In each individual, clinical history, physical examination, leukocyte enzyme activity of □-Gal A, and mutation analysis were performed. Those with a mutation were further investigated by ophthalmological and audiological evaluations, electrocardiography, echocardiogram, urinalysis, and blood tests to determine renal insufficiency. Expression study of the mutant protein was performed using a Pichia pastoris expression system. Results: Four affected males and five symptomatic female carriers were identified. Clinical manifestations included severe neuropathic pain, acroparesthesia, hypo-/hyper-hidrosis, frequent syncope, ischemic stroke, cardiac hypertrophy, corneal dystrophy and cart-wheel cataract, high frequency sensorineural hearing loss, periorbital edema and subcutaneous edema over hands and interphalangeal joints. None had angiokeratoma or renal symptoms. The authors identified a novel mutation, p.L106R, in the GLA gene. Recombinant expression of the mutant protein gave little or no enzyme activity compared to the normal protein. Conclusion: There were intrafamilial clinical variabilities, but consistent findings of the absence of angiokeratoma and renal symptoms, which could represent a unique feature of this particular mutation.