Genetic Screening of Anderson-Fabry Disease in Probands Referred From Multispecialty Clinics.

BACKGROUND: Anderson-Fabry disease (AFD) is a rare X-linked lysosomal storage disease, caused by defects of the alpha-galactosidase A (GLA) gene. AFD can affect the heart, brain, kidney, eye, skin, peripheral nerves, and gastrointestinal tract. Cardiology (hypertrophic cardiomyopathy), neurology (cryptogenic stroke), and nephrology (end-stage renal failure) screening studies suggest the prevalence of GLA variants is 0.62%, with diagnosis confirmation in 0.12%. OBJECTIVES: This study sought to expand screening from these settings to include ophthalmology, dermatology, gastroenterology, internal medicine, pediatrics, and medical genetics to increase diagnostic yield and comprehensively evaluate organ involvement in AFD patients. METHODS: In a 10-year prospective multidisciplinary, multicenter study, we expanded clinical, genetic, and biochemical screening to consecutive patients enrolled from all aforementioned clinical settings. We tested the GLA gene and α-galactosidase A activity in plasma and leukocytes. Inclusion criteria comprised phenotypical traits and absence of male-to-male transmission. Screening was extended to relatives of probands harboring GLA mutations. RESULTS: Of 2,034 probands fulfilling inclusion criteria, 37 (1.8%) were carriers of GLA mutations. Cascade family screening identified 60 affected relatives; clinical data were available for 4 affected obligate carriers. Activity of α-galactosidase A in plasma and leukocytes was diagnostic in male subjects, but not in female subjects. Of the 101 family members harboring mutations, 86 were affected, 10 were young healthy carriers, and 5 refused clinical evaluation. In the 86 patients, involved organs or organ systems included the heart (69%), peripheral nerves (46%), kidney (45%), eye (37%), brain (34%), skin (32%), gastrointestinal tract (31%), and auditory system (19%). Globotriaosylceramide accumulated in organ-specific and non-organ-specific cells in atypical and classic variants, respectively. CONCLUSIONS: Screening probands with clinically suspected AFD significantly increased diagnostic yield. The heart was the organ most commonly involved, independent of the clinical setting in which the patient was first evaluated.

Types of stroke recurrence in patients with ischemic stroke: a substudy from the PRoFESS trial.

BACKGROUND: Risk profiles for stroke recurrence are poorly characterized. AIMS: We determined the variation in the risk and type of recurrent stroke among index ischemic stroke subtypes, and whether index stroke subtype and conventional stroke risk factors were predictors of stroke recurrence. METHODS: Patients enrolled in the Prevention Regimen for Effectively Avoiding Second Strokes trial were included in this study. RESULTS: In 1794 patients' recurrent stroke subtypes were the same as the index stroke in: 48·3% of patients with large artery atherothrombosis stroke; 50% of patients with cardioembolic stroke; 48·7% of patients with small artery occlusion stroke; 8·1% of patients with stroke of other etiology, and 45·3% of patients with undetermined etiology stroke. Patients with cardioembolic stroke, who were unwilling or unable to take oral anticoagulants, had the greatest risk of stroke recurrence. Predictors of stroke recurrence in multivariable analysis were: older age and previous stroke among large artery atherothrombosis strokes; older age, male sex, previous stroke, previous transient ischemic attack, hypertension, diabetes, and tobacco use among small artery occlusion strokes; older age among cardioembolic strokes; atrial fibrillation and anti-diabetic medications among other etiology strokes; older age, previous stroke and atrial fibrillation among undetermined etiology strokes. Predictors of brain hemorrhage as recurrent stroke were index small artery occlusion stroke, older age, previous stroke, and antiplatelet treatment with aspirin plus extended-release dipyridamole. CONCLUSIONS: Risk predictors for stroke recurrence and for brain hemorrhage differ by index ischemic stroke subtype, information that is important when initiating secondary prevention therapy.

Pharmacogenetic testing for guiding de novo phenprocoumon therapy in stroke patients.

BACKGROUND: For many conditions causing transient ischemic attack or minor stroke, secondary prevention with early initiation of oral anticoagulation is indicated. The individual response to coumarins is known to vary widely and is not well predicted by clinical variables. Patients' discharge from hospital care is often delayed only because the therapeutic target range has not been reached yet. A feasible tool to guide coumarin dosing and thereby safely shortening time in hospital is required. METHODS: We established a polymerase chain reaction technique for rapid genotyping of the vitamin K epoxide reductase complex (VKORC1), which is the pharmaceutical target of the coumarins. C283 + 837C -> T (rs2359612) genotypes were determined in 49 patients who underwent de novo oral anticoagulation with phenprocoumon for cerebrovascular disease. Other variables potentially affecting phenprocoumon sensitivity were systematically evaluated. RESULTS: Of 49 genotyped patients, 47 were treated in hospital until an international normalized ratio (INR) of 2-3 was reached. The time and the cumulative dose of phenprocoumon necessary to achieve the target INR both were strongly dependent on the individual C283 + 837C -> T genotype (Kruskal-Wallis test p = 0.0002, and p < 0.0001, respectively). Carriers of the TT genotype reached an INR of 2-3 after a mean time of 3.2 days (n = 5), CT carriers after 4.4 days (n = 27), and CC carriers after 6.5 days (n = 15). No other variable, including body weight, was significantly correlated with the treatment response. CONCLUSION: In patients with cerebrovascular disease, genotyping for VKORC1 alone can strongly predict the individual response to de novo phenprocoumon treatment. The size of the pharmacogenetic test's potential effect on a more efficient use of hospital capacities remains to be shown by a controlled interventional study.