Oxidative stress biomarkers in Fabry disease: is there a room for them?

BACKGROUND: Fabry disease (FD) is an X-linked lysosomal storage disorder, caused by deficient activity of the alpha-galactosidase A enzyme leading to progressive and multisystemic accumulation of globotriaosylceramide. Recent data point toward oxidative stress signalling which could play an important role in both pathophysiology and disease progression. METHODS: We have examined oxidative stress biomarkers [Advanced Oxidation Protein Products (AOPP), Ferric Reducing Antioxidant Power (FRAP), thiolic groups] in blood samples from 60 patients and 77 healthy controls. RESULTS: AOPP levels were higher in patients than in controls (p < 0.00001) and patients presented decreased levels of antioxidant defences (FRAP and thiols) with respect to controls (p < 0.00001). In a small group of eight treatment-naïve subjects with FD-related mutations, we found altered levels of oxidative stress parameters and incipient signs of organ damage despite normal lyso-Gb3 levels. CONCLUSIONS: Oxidative stress occurs in FD in both treated and naïve patients, highlighting the need of further research in oxidative stress-targeted therapies. Furthermore, we found that oxidative stress biomarkers may represent early markers of disease in treatment-naïve patients with a potential role in helping interpretation of FD-related mutations and time to treatment decision.

Mitochondrial DNA haplogroups may influence Fabry disease phenotype.

While the genetic origin of Fabry disease (FD) is well known, it is still unclear why the disease presents a wide heterogeneity of clinical presentation and progression, even within the same family. Emerging observations reveal that mitochondrial impairment and oxidative stress may be implicated in the pathogenesis of FD. To investigate if specific genetic polymorphisms within the mitochondrial genome (mtDNA) could act as susceptibility factors and contribute to the clinical expression of FD, we have genotyped European mtDNA haplogroups in 77 Italian FD patients and 151 healthy controls. Haplogroups H and I, and haplogroup cluster HV were significantly more frequent in patients than controls. However, no correlation with gender, age of onset, organ involvement was observed. Our study seems to provide some evidence of a contribution of mitochondrial variation in FD pathogenesis, at least in Italy.

Prevalence of multiple sclerosis in Verona, Italy: an epidemiological and genetic study.

BACKGROUND AND PURPOSE: Recent multiple sclerosis (MS) prevalence studies classify Italy as a high-risk area without intra-regional latitude effect. OBJECTIVES: To determine MS prevalence in Verona, Italy, and frequency of myelin oligodendrocyte glycoprotein (MOG) gene G511C polymorphism and HLA-DRB1*15 locus in a sample of cases and healthy controls. METHODS: The study area population on the prevalence date (31 December 2001) was 253208 (133508 women, 119700 men). Multiple case sources were examined. Patients fulfilling McDonald's criteria (2001) were included. Crude, age- and sex-specific prevalence rates were computed. MOG G511C polymorphism and HLA-DRB1*15 were determined by standard methods. RESULTS: We identified 270 cases of MS yielding a crude prevalence rate of 106.6/100000 (95% CI: 94-120). Prevalence was higher in women (140.8/100000) than in men (68.5/100000). The age-adjusted prevalence rate standardized to the European population was 96.0/100000. MOG G511C polymorphism did not differ between cases and controls. HLA-DRB1*15 frequency was 58/155 (37%) in cases and 24/157 (15%) in controls (P<0.001). There was no HLA-DRB1*15 influence on susceptibility to other autoimmune disorders. CONCLUSIONS: The high MS prevalence in Verona confirms Italy as a high-risk area with a homogenous distribution across the country. HLA-DRB1*15 is a relevant MS susceptibility locus in the Italian population, possibly with little influence on the occurrence of concomitant autoimmune disorders.

A case of Fabry disease with central nervous system (CNS) demyelinating lesions: a double trouble?

We present the case of a 36-year-old woman affected with Fabry disease (FD), with neuroradiologic and laboratory tests suggestive of a coexistent inflammatory demyelinating disease. Since the age of 23, she presented recurrent neurologic deficits, such as right limb paresthesias, diplopia, and right leg weakness. Magnetic resonance imaging revealed multiple demyelinating lesions in periventricular areas, corpus callosum, and spinal cord. Cerebrospinal fluid analysis showed the presence of oligoclonal bands, while visual-evoked potentials were delayed with preserved morphology. FD is usually considered as a differential diagnosis of multiple sclerosis, but we think that the best explanation of all pathological features in this case is the coexistence of the two diseases.

COX-2 promoter region polymorphisms in multiple sclerosis: lack of association of -765G>C with disease risk.

Cyclooxygenase-2 (COX-2) is extensively expressed in multiple sclerosis lesions suggesting that regulatory variants of the COX-2 gene could be implicated in multiple sclerosis (MS). Screening of the proximal 5' regulatory region and genotyping of -765G>C and -62C>G showed that polymorphisms in this COX-2 region are unlikely to be involved in MS susceptibility.

Neuropathology of cognitively normal elderly.

Despite general agreement about the boundaries of Alzheimer disease (AD), establishing a maximum limit for Alzheimer-type pathology in cognitively intact individuals might aid in defining more precisely the point at which Alzheimer pathology becomes clinically relevant. In this study, we examined the neuropathological changes in the brains of 39 longitudinally followed. cognitively normal elderly individuals (24 women, 15 men; age range 74-95, median 85 years). Neuropathological changes of the Alzheimer type were quantified by determining neurofibrillary tangle (NFT) staging by the method of Braak and Braak and by quantification of the abundance of diffuse, cored, and neuritic plaque burden using the scheme developed by the Consortium to Establish a Registry for Alzheimer Disease (CERAD). Vascular, Lewy body, and argyrophilic grain pathology were also assessed. We found 34 subjects (87%) with a Braak stage

Myelin oligodendrocyte glycoprotein polymorphisms and multiple sclerosis.

A detailed analysis of the coding sequences of myelin oligodendrocyte glycoprotei (MOG) gene was performed in multiple sclerosis (MS) patients and in control individuals and three new polymorphisms are described: T636C, nt 571+77C-->T (IVS 4), and nt 710-44A-->G (IVS 6). Screening studies demonstrated that T636C was present in three MS patients and in no control individual and that polymorphisms nt 571+77C-->T (IVS 4), and nt 710-44A-->G (IVS 6), were present with no significant frequency differences in MS patients and control individuals. No mutations were found after sequencing the coding sequences of the extracellular domain of MOG gene in 20 MS patients and 20 control individuals. Screening studies were also performed for known polymorphisms: G15A, Val142Leu, nt 571+68A-->G (IVS 4), and 571+92C-->G (IVS 4). Polymorphism Val 142 Leu, which is linked to nt 571+68A-->G (IVS 4), resulted under-represented in MS patients.

Prevalence of dementia and apolipoprotein e genotype distribution in the elderly of buttapietra, verona province, Italy.

We investigated the prevalence of dementia and the apolipoprotein E (APOE) genotype distribution in the elderly of Buttapietra, a village near Verona, Italy. All residents over the age of 74 (n = 238), including those who were institutionalized, were studied using a direct-contact, single-phase design. The overall prevalence of dementia, clinically defined by DSM-III-R criteria, was 15.8 cases per 100 population, with age-specific figures increasing steeply with advancing age in both sexes. Alzheimer's disease (AD) was the most frequent dementing disorder (43%). APOE genotyping was determined after DNA amplification by restriction isotyping. We found that the epsilon4 allele and the epsilon3/epsilon4 genotype were associated with all types of dementia, although only the association of epsilon3/epsilon4 with AD reached statistical significance (odds ratio 4.5, 95% confidence interval 1.3-16.1). However, as reported in other Mediterranean countries, the frequency of the epsilon4 allele in our population was low (8.9%), suggesting that the population-attributable risk for AD, at least for elderly individuals (> or =75 years), could be small.

A novel 4-bp deletion creates a premature stop codon and dramatically decreases HEXB mRNA levels in a severe case of Sandhoff disease.

We present the molecular genetic analysis of an infantile-onset Sandhoff disease patient. Genomic DNA amplification, heteroduplex analysis, cloning and sequencing revealed a 4-bp deletion in exon 4 (497 DeltaAGTT). The result is a frameshift mutation that leads to a stop codon in exon 5. This mutation is associated with a dramatic decrease of HEXB mRNA levels.

Myelin oligodendrocyte glycoprotein (MOG) polymorphisms and adrenoleukodystrophy.

We describe four novel sequence variants in the Myelin Oligodendrocyte Glycoprotein (MOG) gene. A total of six sequence variants of the MOG gene were identified in eleven out of 44 ALD patients investigated: G15A, CTC repeat in exon 1, Val142Leu, Val145Ile, 551+68A-->G and 551+77C-->T. Screening studies demonstrated that all these polymorphisms are present in 50 unaffected control male individuals of the same population and in the different phenotypes of ALD patients, indicating that they do not contribute to phenotype variability in ALD.

Novel consensus sequence for the Golgi apparatus casein kinase, revealed using proline-rich protein-1 (PRP1)-derived peptide substrates.

Previous studies have shown that the Golgi apparatus casein kinase (G-CK) recognizes phosphoacceptor sites specified by the triplet SXE/Sp, which is found in several phosphoproteins, besides casein itself. In the present study, we report that G-CK can phosphorylate, with comparable efficiency, sequences surrounding Ser-22 of salivary proline-rich protein-1 (PRP1), which do not conform to the SXE/Sp motif. By using a series of peptide substrates derived from the PRP1 Ser-22 site, we also have shown that the optimal consensus sequence recognized by G-CK in this case was SXQXX(D/E)3, where the acidic residues at positions n+5 to n+7 and, to a lesser extent, the glutamine residue at position n+2 are the critical determinants.

Detection of mutations in the ALD gene (ABCD1) in seven Italian families: description of four novel mutations.

The study describes the mutations causing adrenoleukodystrophy in seven Italian families. Four missense mutations leading to amino acid substitutions, two frameshift mutations leading to a premature termination signal, and a splicing mutation were identified. Mutations 2014C>T (P543L), 2053A>G (Q556A), 673-674insCC, and 1874+1G>A are described for the first time in this report. Mutations 1638C>T (R418W), 1588G>A(R401Q), and 1801-1802delAG are already known to be link to ALD.

Neuroaxonal dystrophy with dystonia and pallidal involvement.

Infantile neuroaxonal dystrophy (INAD) is an autosomal recessive disease of infantile onset, characterised by progressive clinical course, multi-systemic involvement and widespread presence of dystrophic axons in both the central and peripheral nervous system. Clinical, neurophysiological and neuroradiological criteria of the disease are established, but the occurrence of atypical cases is known. Since the availability of molecular markers is still lacking, diagnostic evidence in vivo is provided by the presence of specific axonal lesions distally in the peripheral nerve fibres. In two children who had a protracted course of the disease with dystonic postures of the upper limbs and showed dystrophic axons following sural nerve biopsy, bilateral pallidal hypointensity was observed after T2-weighted MRI scans. These findings are consistent with iron deposition, and are usually observed in Hallervorden-Spatz syndrome (HSS), a condition which is also characterised by dystrophic axons diffusely present in the central nervous system, but without peripheral nervous system involvement. These observations raise the issue of different phenotypes of INAD, and are consistent with the existence of intermediate forms between INAD and HSS. Altered mechanisms of iron storage and transport to and from the cellular compartments may play a role in the pathogenesis of the disease.

Two novel frameshift mutations in the adrenoleukodystrophy gene in Italian patients.

Two novel frameshift adrenoleukodystrophy mutations in two families were identified: a complex dinucleotide deletion/tetranucleotide insertion at 1116 TC-->GAGA (codon 244 [serine]) and an AG deletion at nucleotide 1462 (codon 359 [glutamic acid]). Both mutations are predicted to cause premature termination of protein synthesis. The patients were affected by childhood cerebral adrenoleukodystrophy and by adrenomyeloneuropathy with mild Addison disease, respectively.

Two novel missense mutations causing adrenoleukodystrophy in Italian patients.

The authors present two new missense mutations in exon 1 of the adrenoleukodystrophy (ALD) gene. The first, a C813T transition, results in the substitution Pro143 Ser in the third putative transmembrane domain of the adrenoleukodystrophy protein (ALDP) in an adult onset case. The second, a de novo C709T transition, results in a substitution Ser 108 Leu between the second and the third putative transmembrane segments, in a childhood case.

Transduced fibroblasts and metachromatic leukodystrophy lymphocytes transfer arylsulfatase A to myelinating glia and deficient cells in vitro.

Metachromatic leukodystrophy (MLD) is a lysosomal storage disease, caused by deficiency of arylsulfatase A (ASA), that manifests primarily in the white matter of the nervous system. Currently, no specific treatment exists that will reverse its fatal outcome. Replacement therapy has been hampered by the blood-brain barrier (BBB). To circumvent this problem we designed an ex vivo gene therapy strategy that includes the retrovirus-mediated ASA transduction of cells, such as activated lymphocytes, that are able to traverse the BBB or other membranes of the CNS. For this purpose, two recombinant retroviruses based on the pLXSN vector were produced, containing the wild-type ASA cDNA or a pseudodeficiency ASA cDNA, which encodes a smaller enzyme with normal activity. After transduction, ASA activity increased more than 100-fold in fibroblasts from an MLD patient. Furthermore, ASA-transduced MLD PBLs expressed 30 times higher ASA activity when compared with control PBLs. Moreover, cell culture experiments demonstrated that transduced fibroblasts could efficiently transfer ASA to deficient cells across a transwell barrier, whereas transduced MLD lymphocytes could transfer ASA to deficient fibroblasts only by direct cell-to-cell contact. Finally, ASA was taken up by normal oligodendrocytes and Schwann cells, the target myelinating glial cells for therapy in MLD. These data suggest possible short-term strategies for transfer of ASA into the CNS via transduced autologous cells while long-term strategies, related to autologous transduced bone marrow transplant, take effect in patients.

Molecular genetic characterization of two metachromatic leukodystrophy patients who carry the T799G mutation and show different phenotypes; description of a novel null-type mutation.

Metachromatic leukodystrophy (MLD) is an autosomal recessive storage disease caused by deficiency of the lysosomal enzyme, arylsulfatase A. Two common mutations causing MLD have been characterized and correlations between phenotype and genotype have been established. A third common mutation, T799G, has also been identified in European MLD patients, and is associated with the late-onset forms of the disease. We report the molecular analysis of two Italian MLD patients, with juvenile and adult onset of the disease, respectively, who carried the T799G mutation in compound heterozygosity with different null mutations. A novel rapid mutation detection method is demonstrated for patient screening. One patient has a novel mutation, a T553C [corrected] transition that results in the substitution of Pro for Leu at codon 135, and produces no enzymatic activity in transfection experiments.