Maria Clara Sa Miranda

To identify patients with Fabry's disease (FD) within patients with kidney dysfunction, submitted to hemodialysis. Patients under hemodialysis were screened using a combined enzymatic α-Gal A assay and dried blood spot samples to determine GLA genotype. A total of 3,650 samples (18.5% of all patients under hemodialysis in Spain) were tested and 11 new unrelated FD patients (4 males and 7 females) were diagnosed. 66 relatives of 11 patients were tested and 23 new FD patients were identified. This study allowed the diagnosis of 34 FD patients. Among the 11 unrelated FD patients, 5 presented the same R118C mutation and one novel mutation was detected: D109G. This study reveals the need for screening for FD in all patients under hemodialysis for unknown causes and indicates that the incidence and prevalence of FD are underestimated so far.

Summary: The Niemann‐Pick type C is a rare metabolic disease with a severe neurodegenerative phenotype characterized by an accumulation of high amounts of lipids (cholesterol and sphingolipids) in the late endosomal/lysosomal network. It is caused by loss‐of‐function point mutations in either NPC1 or NPC2, which seem to mediate proper intracellular lipid transport through endocytic pathway. In this study, we show that yeast cells lacking Ncr1p, an orthologue of mammalian NPC1, exhibited a higher sensitivity to hydrogen peroxide and a shortened chronological lifespan. These phenotypes were associated with increased levels of oxidative stress markers, decreased levels of antioxidant defences and mitochondrial dysfunctions. Moreover, we report that Ncr1p‐deficient cells displayed high levels of long chain bases (LCB), and that Sch9p‐phospho‐T570 and Sch9p levels increased in ncr1Δ cells through a mechanism regulated by Pkh1p, a LCB‐activated protein kinase. Notably, deletion of PKH1 or SCH9 suppressed ncr1Δ phenotypes but downregulation of de novo sphingolipid biosynthesis had no protective effect, suggesting that LCBs accumulation may result from an increased turnover of complex sphingolipids. These results suggest that sphingolipid signalling through Pkh1p‐Sch9p mediate mitochondrial dysfunction, oxidative stress sensitivity and shortened chronological lifespan in the yeast model of Niemann‐Pick type C disease.

Characteristic cardiac valve abnormalities and left ventricular hypertrophy are present in untreated patients with mucopolysaccharidosis type VI (MPS VI). Cardiac ultrasound was performed to investig...