Eye Movement Impairment Recovery in a Gaucher Patient Treated with Miglustat

In Gaucher Disease (GD) the enzyme (imiglucerase) replacement therapy (ERT) is not able to stop the progression of the neurological involvement, while the substrate reduction therapy (SRT), performed by N-Butyldeoxynojirimycin (miglustat), is an alternative that should be evaluated. Two sisters, presenting the same genotype (R353G/R353G), were diagnosed as suffering from GD; one of them later developed neurological alterations identified by quantitative saccadic eye movements analysis. The aim of the study was to quantitatively measure the miglustat effects in this GD neurological patient. Eye movement analysis during subsequent controls was performed by estimating the characteristic parameters of saccadic main sequence. The study demonstrates that the SRT alone can be effective in GD3. Moreover, it confirms that quantitative eye movement analysis is able to precociously identify also slight neurological alterations, permitting more accurate GD classification

Altered localization and functionality of TAR DNA Binding Protein 43 (TDP-43) in niemann- pick disease type C

Niemann-Pick type C (NPC) disease is a lysosomal storage disorder characterized by the occurrence of visceral and neurological symptoms. At present, the molecular mechanisms causing neurodegeneration in this disease are unknown. Here we report the altered expression and/or mislocalization of the TAR-DNA binding protein 43 (TDP-43) in both NPC mouse and in a human neuronal model of the disease. We also report the neuropathologic study of a NPC patient's brain, showing that while TDP-43 is below immunohistochemical detection in nuclei of cerebellar Purkinje cells, it has a predominant localization in the cytoplasm of these cells. From a functional point of view, the TDP-43 mislocalization, that occurs in a human experimental neuronal model system, is associated with specific alterations in TDP-43 controlled genes. Most interestingly, treatment with N-Acetyl-cysteine (NAC) or beta-cyclodextrin (CD) can partially restore TDP-43 nuclear localization. Taken together, the results of these studies extend the role of TDP-43 beyond the Amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD)/Alzheimer disease (AD) spectrum. These findings may open novel research/therapeutic avenues for a better understanding of both NPC disease and the TDP-43 proteinopathy disease mechanism

Niemann-Pick type C disease mutations of NPC1 gene and evidence of abnormal expression of some mutant alleles in fibroblasts

We analyzed Niemann-Pick type C disease 1 (NP44406) gene in 12 patients with Niemann-Pick type C disease by sequencing both cDNA obtained from fibroblasts and genomic DNA. All the patients were compound heterozygotes. We found 15 mutations, eight of which previously unreported. The comparison of cDNA and genomic DNA revealed discrepancies in some subjects. In two unrelated patients carrying the same mutations (P474L and nt 2972del2) only one mutant allele (P474L), was expressed in fibroblasts. The mRNA corresponding to the other allele was not detected even in cells incubated with cycloheximide. The promoter variants (−1026T/G and −1186T/C or −238 C/G), found to be in linkage with 2972del2 allele do not explain the lack of expression of this allele, as they were also found in control subjects. In another patient, (N1156S/Q922X) the N1156S allele was expressed in fibroblasts while the expression of the other allele was hardly detectable. In a fourth patient cDNA analysis revealed a point mutation in exon 20 (P1007A) and a 56 nt deletion in exon 22 leading to a frameshift and a premature stop codon. The first mutation was confirmed in genomic DNA; the second turned out to be a T→G transversion in exon 22, predicted to cause a missense mutation (V1141G). In fact, this transversion generates a donor splice site in exon 22, which causes an abnormal pre-mRNA splicing leading to a partial deletion of this exon. In some NPC patients, therefore, the comparison between cDNA and genomic DNA may reveal an unexpected expression of some mutant alleles of NPC1 gene

Identification and Characterization of 15 Novel GALC Gene Mutations Causing Krabbe Disease

The characterization of the underlying GALC gene lesions was performed in 30 unrelated patients affected by Krabbe disease, an autosomal recessive leukodystrophy caused by the deficiency of lysosomal enzyme galactocerebrosidase. The GALC mutational spectrum comprised 33 distinct mutant (including 15 previously unreported) alleles. With the exception of 4 novel missense mutations that replaced evolutionarily highly conserved residues (p.P318R, p.G323R, p.I384T, p.Y490N), most of the newly described lesions altered mRNA processing. These included 7 frameshift mutations (c.61delG, c.408delA, c.521delA, c.1171_1175delCATTCinsA, c.1405_1407delCTCinsT, c.302_308dupAAATAGG, c.1819_1826dupGTTACAGG), 3 nonsense mutations (p.R69X, p.K88X, p.R127X) one of which (p.K88X) mediated the skipping of exon 2, and a splicing mutation (c.1489+1G>A) which induced the partial skipping of exon 13. In addition, 6 previously unreported GALC polymorphisms were identified. The functional significance of the novel GALC missense mutations and polymorphisms was investigated using the MutPred analysis tool. This study, reporting one of the largest genotype-phenotype analyses of the GALC gene so far performed in a European Krabbe disease cohort, revealed that the Italian GALC mutational profile differs significantly from other populations of European origin. This is due in part to a GALC missense substitution (p.G553R) that occurs at high frequency on a common founder haplotype background in patients originating from the Naples region. © 2010 Wiley-Liss, Inc

Respiratory muscle training with enzyme replacement therapy improves muscle strength in late - onset Pompe disease.

Background Pompe disease is an autosomal recessive metabolic disorder caused by the deficiency of the lysosomal enzyme acid \u3b1-glucosidase. This deficiency leads to glycogen accumulation in the lysosomes of muscle tissue causing progressive muscular weakness particularly of the respiratory system. Enzyme replacement therapy (ERT) has demonstrated efficacy in slowing down disease progression in infants. Despite the large number of studies describing the effects of physical training in juvenile and adult late onset Pompe disease (LOPD). There are very few reports that analyze the benefits of respiratory muscle rehabilitation or training. Methods The effectiveness of respiratory muscle training was investigated using a specific appliance with adjustable resistance (Threshold). The primary endpoint was effect on respiratory muscular strength by measurements of MIP and MEP. Eight late-onset Pompe patients (aged 13 to 58 years; 4 female, 4 male) with respiratory muscle deficiency on functional respiratory tests were studied. All patients received ERT at the dosage of 20 mg/kg/every 2 weeks and underwent training with Threshold at specified pressures for 24 months. Results A significant increase in MIP was observed during the follow-up of 24 month: 39.6 cm H2O (+ 25.0%) at month 3; 39.5 cm H2O (+ 24.9%) at month 6; 39.1 cm H2O (+ 23.7%) at month 9; 37.3 cm H2O (+ 18.2%) at month 12; and 37.3 cm H2O (+ 17.8%) at month 24. Median MEP values also showed a significant increase during the first 9 months: 29.8 cm H2O, (+ 14.3%) at month 3; 31.0 cm H2O (+ 18.6) at month 6; and 29.5 cm H2O (+ 12.9) at month 9. MEP was then shown to be decreased at months 12 and 24; median MEP was 27.2 cm H2O (+ 4.3%) at 12 months and 26.6 cm H2O (+ 1.9%) at 24 months. The FVC remain stable throughout the study. Conclusion An increase in respiratory muscular strength was demonstrated with Threshold training when used in combination with ERT