T1 hyperintensity in the pulvinar: key imaging feature for diagnosis of Fabry disease.
(49/381)
BACKGROUND AND PURPOSE: Fabry disease (FD) is an inborn error of glycosphingolipid metabolism. To date, no specific neuroimaging features have been elucidated to help in making the diagnosis of this disorder. The purpose of this study was to determine whether the finding of T1 shortening in the lateral pulvinar is a useful finding in the imaging diagnosis of FD and to deduce the relationship of this finding to the pathophysiology of the disease. METHODS: We studied T1- and T2-weighted images obtained in ten patients (nine male and one female) with FD with an age range of 19-59 years. The images were examined for anatomic aberrations and areas of abnormal signal intensity (SI) in both gray matter and white matter. The SI of deep gray matter was evaluated qualitatively and semiquantitatively, relative to the SI of CSF or the genu of the corpus callosum. Gradient echo MR images and axial noncontrast CT images were available for one patient. RESULTS: Seven of 10 patients showed small areas of T2 prolongation in the white matter of the cerebral hemispheres. Despite the known propensity for vascular disease in these patients, only one had cortical infarction. Bilateral T1 shortening in the lateral pulvinar was recognized in at least seven patients, all over the age of 30 years, who also had small areas of T2 prolongation in the white matter. CT and gradient echo images in one patient revealed no evidence of calcification or metallic deposits in the pulvinar. CONCLUSION: Bilateral T1 shortening in the lateral pulvinar is a common finding in FD and may be useful in suggesting this diagnosis. (+info)
Fabry disease: novel alpha-galactosidase A 3'-terminal mutations result in multiple transcripts due to aberrant 3'-end formation.
(50/381)
Mutations in the gene that encodes the lysosomal exoglycohydrolase, alpha-galactosidase A (alpha-GalA), cause Fabry disease, an X-linked recessive inborn error of glycosphingolipid catabolism. Human alpha-GalA is one of the rare mammalian genes that has its polyadenylation signal in the coding sequence and lacks a 3' untranslated region (UTR). We identified two novel frameshift mutations, 1277delAA (del2) and 1284delACTT (del4), in unrelated men with classical Fabry disease. Both mutations occurred in the 3' terminus of the coding region and obliterated the termination codon, and del2 also altered the polyadenylation signal. To characterize these mutations, 3' rapid amplification of cDNA ends (RACE) and polymerase chain reactions (PCR) were performed, and the amplicons were subcloned and sequenced. Both mutations generated multiple transcripts with various lengths of 3' terminal sequences, some elongating approximately 1 kb. Mutant transcripts were classified as follows: type I transcripts had terminal in-frame thymidines that created termination codons when polyadenylated, type II had downstream termination codons within the elongated alpha-GalA sequence, and type III, the most abundant, lacked termination codons at their 3' ends. To determine if the type III transcripts were degraded by the recently described cytosolic messenger RNA degradation pathway for messages lacking termination codons, northern blot analysis was performed. However, the finding of similar levels of nuclear and cytoplasmic alpha-GalA mRNA in normal and patient lymphoblasts suggested that mRNA degradation did not result from either mutation. Expression of representative transcript types revealed differences in intracellular localization and/or protein stability and catalytic activity, with most mutant proteins being nonfunctional. Characterization of these 3' mutations identified a novel molecular mechanism causing classical Fabry disease. (+info)
Increased signal intensity in the pulvinar on T1-weighted images: a pathognomonic MR imaging sign of Fabry disease.
(51/381)
BACKGROUND AND PURPOSE: Fabry disease is a multisystem X-linked disorder characterized clinically by angiokeratoma, corneal and lenticular abnormalities, acroparesthesia, and renal and cardiac dysfunction and stroke. We sought to describe novel neuroimaging characteristics of Fabry disease. METHODS: Neuroradiologic records of 104 hemizygous patients with Fabry disease evaluated between 1994 and 2002 were reviewed. In total, 94 MR studies consisting of T1- and T2-weighted images were examined for the presence of hyperintensity on the T1-weighted images. Additional CT, gradient-echo (T2*-weighted), and fat-suppression MR studies were reviewed to characterize further the T1 abnormality in selected patients. In some patients, cerebral blood flow (CBF) was quantified by using arterial spin tagging (AST). RESULTS: Overall, 22 patients ( approximately 23%) demonstrated pulvinar hyperintensity on T1-weighted images; the frequency increased with age to over 30% by age 50 years. Susceptibility-weighted T2* studies demonstrated a low-signal-intensity abnormality in the pulvinar in the more severe cases, whereas CT demonstrated the pulvinar to be mineralized. CT attenuation corresponded with an increasing signal intensity on T1-weighted images. Posterior circulation CBF was found to be elevated on individual AST studies, especially in the thalamus. CONCLUSION: Hyperintensity in the pulvinar on T1-weighted images is a common finding in Fabry disease, likely reflecting the presence of calcification. Although other minreralizing abnormalities may result in calcification of deep gray nuclei, exclusive involvement of the pulvinar may be distinctively characteristic to Fabry disease. Increased CBF in the posterior circulation, particularly the thalamus, suggests that the dystrophic calcification is secondary to cerebral hyperperfusion and selective vulnerability of the pulvinar and adjacent thalamic nuclei. The finding of isolated pulvinar hyperintensity on T1-weighted images should suggest Fabry disease, particularly when seen in conjunction with other nonspecific neuroradiologic manifestations of the disease. (+info)
Fabry disease in a renal allograft.
(52/381)
Incidental findings of rare diseases in organ donors can be seen in allograft biopsies that may have profound implications for the recipient and for the donor and their family. Fabry disease is an X-linked recessive lipid storage disease with cardiovascular, renal and lenticular abnormalities. Phenotypic expression in female heterozygote carriers depends on lyonization. Minimal data exists on outcomes of transplanted kidneys from carriers of Fabry disease. We report a patient with ESRD secondary to focal sclerosis who received a HLA-identical transplant from her sister whose pretransplant donor work up was completely negative. Post-transplant, while pregnant, the recipient developed increasing proteinuria and was biopsied. The biopsy showed extensive myelin figures consistent with Fabry disease. Subsequent genetic, enzymatic and pedigree analysis confirmed the diagnosis in the recipient, the donor and the donor's son. Two years post-transplant the patient continues to have non-nephrotic range proteinuria with normal serum creatinine. (+info)
alpha-Galactosidase A deficiency in Dutch patients on dialysis: a critical appraisal of screening for Fabry disease.
(53/381)
INTRODUCTION: Fabry disease or alpha-galactosidase A (alpha-Gal A) deficiency is an X-linked lysosomal storage disorder that often leads to renal insufficiency in males and occasionally in females. The disease is rare, but its prevalence may be underestimated due to its variable clinical picture. Enzyme supplementation therapy with rHu-alphaGal A is currently available. Limited experience has so far shown that therapy may at best stabilize renal function. Despite these preliminary findings, much effort is being put into screening high-risk groups for undiagnosed alpha-Gal A deficiency. We studied the prevalence of alpha-Gal A deficiency in a Dutch dialysis cohort to establish possible underdiagnosis. We discuss the benefits of screening for Fabry disease. METHODS: Activity of alpha-Gal A in whole blood was measured in a group of 508 male Dutch dialysis patients. RESULTS: Of the 508 patients studied only one patient, already known with Fabry disease, had a alpha-Gal A deficiency, a prevalence of 0.22% (95 CI 0-1.1%). CONCLUSIONS: No undiagnosed Fabry patients were found, indicating that in our studied cohort there is no large-scale underestimation of its prevalence. Even though screening of dialysis patients for Fabry disease might identify patients who remain otherwise unrecognized, screening of high-risk populations for alpha-Gal A deficiency should be carried out with caution since long-term efficacy of treatment is currently unknown. (+info)
Improvement of cardiac function during enzyme replacement therapy in patients with Fabry disease: a prospective strain rate imaging study.
(54/381)
BACKGROUND: Enzyme replacement therapy (ERT) has been shown to enhance microvascular endothelial globotriaosylceramide clearance in the hearts of patients with Fabry disease. Whether these results can be translated into an improvement of myocardial function has yet to be demonstrated. METHODS AND RESULTS: Sixteen patients with Fabry disease who were treated in an open-label study with 1.0 mg/kg body weight of recombinant alpha-Gal A (agalsidase beta, Fabrazyme) were followed up for 12 months. Myocardial function was quantified by ultrasonic strain rate imaging to assess radial and longitudinal myocardial deformation. End-diastolic thickness of the left ventricular posterior wall and myocardial mass (assessed by magnetic resonance imaging, n=10) was measured at baseline and after 12 months of ERT. Data were compared with 16 age-matched healthy controls. At baseline, both peak systolic strain rate and systolic strain were significantly reduced in the radial and longitudinal direction in patients compared with controls. Peak systolic strain rate increased significantly in the posterior wall (radial function) after one year of treatment (baseline, 2.8+/-0.2 s(-1); 12 months, 3.7+/-0.3 s(-1); P<0.05). In addition, end-systolic strain of the posterior wall increased significantly (baseline, 34+/-3%; 12 months, 45+/-4%; P<0.05). This enhancement in radial function was accompanied by an improvement in longitudinal function. End-diastolic thickness of the posterior wall decreased significantly after 12 months of treatment (baseline, 13.8+/-0.6 mm; 12 months, 11.8+/-0.6 mm; P<0.05). In parallel, myocardial mass decreased significantly from 201+/-18 to 180+/-21 g (P<0.05). CONCLUSIONS: These results suggest that ERT can decrease left ventricular hypertrophy and improve regional myocardial function. (+info)
Fabry's disease.
(55/381)
A 20-year-old man presented with generalized acquired anhidrosis and heat intolerance which was confirmed by a sweat test. Other clinical features included severe pain of the extremities and cutaneous angiokeratomas. On electronmicroscopy, granules specific for Fabry's disease were observed in the endothelial cells. Biochemical examination revealed a decreased level of serum alpha-galactosidase A. These findings confirmed the diagnosis of Fabry's disease. (+info)
Fabry's disease with complete atrioventricular block: histological evidence of involvement of the conduction system.
(56/381)
A 63 year old man with complete atrioventricular block was diagnosed as having Fabry's disease. A short PR interval is a common electrocardiographic finding in Fabry's disease, but complete atrioventricular block is a very rare complication. Necropsy indicated that lipid accumulation in the atrioventricular conduction system was the probable cause of this patient's atrioventricular block. (+info)