Stefan Wieczorek

Veszprém Megyei Csolnoky Ferenc Kórház Nonprofit ZRT., Veszprém, Veszprem megye, Hungary

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Publications (49)164.52 Total impact

  • Article: The S18Y polymorphism in the UCHL1 gene is a genetic modifier in Huntington’s disease
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    ABSTRACT: An expanded polyglutamine stretch in the huntingtin protein has been identified as the pathogenetic cause of Huntington's disease (HD). Although the length of the expanded polyglutamine repeat is inversely correlated with the age-at-onset, additional genetic factors are thought to modify the variance in the disease onset. As linkage analysis suggested a modifier locus on chromosome 4p, we investigated the functional relevance of S18Y polymorphism of the ubiquitin carboxy-terminal hydrolase L1 in 946 Caucasian HD patients. In this group, the allelic variation on locus S18Y is responsible for 1.1% of the variance in the HD age-at-onset, and the rare Y allele is associated with younger-aged cases.
    Neurogenetics 04/2012; 7(1):27-30. · 3.35 Impact Factor
  • Article: Age at onset in Huntington’s disease: replication study on the associations of ADORA2A, HAP1 and OGG1
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    ABSTRACT: In previous candidate gene studies, associations of the age at onset (AO) in Huntington disease (HD) have been reported with genetic variations in the genes encoding adenosinergic A2A receptor (ADORA2A), human huntingtin-associated protein-1 (HAP1) and the single base excision repair enzyme, 7,8-dihydro-8-oxoguanine-DNA glycosylase (OGG1). Here, we sought to replicate these associations in an established study population of 419 unrelated German HD patients. AO was defined as the age at which the first motor signs of HD appeared, motor AO (mAO). For 215 patients, also information about the first behavioural or cognitive signs of HD was available, so that we also tested for an association with the earliest AO. No association was found with OGG1. For HAP1, we found modest evidence for association with the same risk allele as in the original sample and mAO. Yet, we replicated the previously reported association between the original ADORA2A polymorphism when using the earliest AO. Additionally, we identified new associations in the same gene, thus further supporting the potential contribution of ADORA2A to the pathogenesis of HD. KeywordsHuntington disease-Age at onset-Modifier genes-Polymorphism
    Neurogenetics 04/2012; 11(4):435-439. · 3.35 Impact Factor
  • Article: Polymorphisms in genes encoding leptin, ghrelin and their receptors in German multiple sclerosis patients.
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    ABSTRACT: Multiple sclerosis (MS) is a neuro-inflammatory, autoimmune disease influenced by environmental and polygenic components. There is growing evidence that the peptide hormone leptin, known to regulate energy homeostasis, as well as its antagonist ghrelin play an important role in inflammatory processes in autoimmune diseases, including MS. Recently, single nucleotide polymorphisms (SNPs) in the genes encoding leptin, ghrelin and their receptors were evaluated, amongst others, in Wegener's granulomatosis and Churg-Strauss syndrome. The Lys656Asn SNP in the LEPR gene showed a significant but contrasting association with these vasculitides. We therefore aimed at investigating these polymorphisms in a German MS case-control cohort. Twelve SNPs in the LEP, LEPR, GHRL and GHSR genes were genotyped in 776 MS patients and 878 control subjects. We found an association of a haplotype in the GHSR gene with MS that could not be replicated in a second cohort. Otherwise, no significant differences in allele or genotype frequencies were observed between patients and controls in this particular cohort. Thus, the present results do not support the hypothesis that genetic variation in the leptin/ghrelin system contributes substantially to the pathogenesis of MS. However, a modest effect of GHSR variation cannot be ruled out and needs to be further evaluated in future studies.
    Molecular and Cellular Probes 06/2011; 25(5-6):255-9. · 2.08 Impact Factor
  • Article: Are there specific genetic risk factors for the different forms of ANCA-associated vasculitis?
    Annals of the rheumatic diseases 04/2011; 70(4):707-8. · 8.11 Impact Factor
  • Article: NMDA receptor gene variations as modifiers in Huntington disease: a replication study.
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    ABSTRACT: Several candidate modifier genes which, in addition to the pathogenic CAG repeat expansion, influence the age at onset (AO) in Huntington disease (HD) have already been described. The aim of this study was to replicate association of variations in the N-methyl D-aspartate receptor subtype genes GRIN2A and GRIN2B in the "REGISTRY" cohort from the European Huntington Disease Network (EHDN). The analyses did replicate the association reported between the GRIN2A rs2650427 variation and AO in the entire cohort. Yet, when subjects were stratified by AO subtypes, we found nominally significant evidence for an association of the GRIN2A rs1969060 variation and the GRIN2B rs1806201 variation. These findings further implicate the N-methyl D-aspartate receptor subtype genes as loci containing variation associated with AO in HD.
    PLoS currents. 01/2011; 3:RRN1247.
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    Article: Eotaxin-3 in Churg-Strauss syndrome: a clinical and immunogenetic study.
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    ABSTRACT: To determine the potential of eotaxin-3 as a diagnostic marker for active disease and genetic susceptibility factor for Churg-Strauss syndrome (CSS). A total of 37 patients with active, relapsed or inactive CSS, 123 healthy controls and 138 disease controls were studied. Clinical data were collected and serum levels of eotaxin-3 were determined. Ex vivo stability of eotaxin-3 in serum samples was tested. Furthermore, the association of single nucleotide polymorphisms (SNPs) in the eotaxin-3 gene with CSS was determined in 161 CSS patients and 124 healthy controls. Serum eotaxin-3 was highly elevated in active CSS patients. Neither eosinophilic diseases nor other small-vessel vasculitides were associated with high serum eotaxin-3 levels. Receiver operating characteristic curve analysis determined a sensitivity and specificity of 87.5 and 98.6% at a cut-off level of 80 pg/ml. None of the tested SNPs within the eotaxin-3 gene influenced the susceptibility to develop CSS. Serum eotaxin-3 is a sensitive and specific marker for the diagnosis of active CSS suitable for routine clinical practice. Previously described SNPs in the eotaxin-3 gene do not predict the risk of developing CSS.
    Rheumatology (Oxford, England) 01/2011; 50(10):1823-7. · 4.24 Impact Factor
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    Article: PGC-1alpha downstream transcription factors NRF-1 and TFAM are genetic modifiers of Huntington disease.
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    ABSTRACT: Huntington disease (HD) is an inherited neurodegenerative disease caused by an abnormal expansion of a CAG repeat in the huntingtin HTT (HD) gene. The primary genetic determinant of the age at onset (AO) is the length of the HTT CAG repeat; however, the remaining genetic contribution to the AO of HD has largely not been elucidated. Recent studies showed that impaired functioning of the peroxisome proliferator-activated receptor gamma coactivator 1a (PGC-1alpha) contributes to mitochondrial dysfunction and appears to play an important role in HD pathogenesis. Further genetic evidence for involvement of PGC-1alpha in HD pathogenesis was generated by the findings that sequence variations in the PPARGC1A gene encoding PGC-1alpha exert modifying effects on the AO in HD. In this study, we hypothesised that polymorphisms in PGC-1alpha downstream targets might also contribute to the variation in the AO. In over 400 German HD patients, polymorphisms in the nuclear respiratory factor 1 gene, NRF-1, and the mitochondrial transcription factor A, encoded by TFAM showed nominally significant association with AO of HD. When combining these results with the previously described modifiers rs7665116 in PPARGC1A and C7028T in the cytochrome c oxidase subunit I (CO1, mt haplogroup H) in a multivariable model, a substantial proportion of the variation in AO can be explained by the joint effect of significant modifiers and their interactions, respectively. These results underscore that impairment of mitochondrial function plays a critical role in the pathogenesis of HD and that upstream transcriptional activators of PGC-1alpha may be useful targets in the treatment of HD.
    Molecular Neurodegeneration 01/2011; 6(1):32. · 4.28 Impact Factor
  • Article: Genetic variations in the genes encoding receptor activator nuclear factor κ B (RANK), receptor activator nuclear factor κ B ligand (RANKL) and osteoprotegerin (OPG) in patients with psoriasis and psoriatic arthritis: a case-control study.
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    ABSTRACT: Psoriasis (Ps) and psoriatic arthritis (PsA) are diseases of unknown origin. However, the receptor activator nuclear factor κ B ligand (RANKL) might play a key role in the pathomechanisms of the disease. Our aim was to study seven single nucleotide polymorphisms (SNP) in the genes encoding for receptor activator nuclear factor κ B (RANK, two SNP), osteoprotegerin (OPG, two SNP) and RANKL (three SNP in patients with Ps and PsA). A case-control study with 156 Ps patients (45 with PsA) and 516 healthy blood donors was conducted to evaluate an association of the SNP with Ps and PsA by genotyping of DNA by polymerase chain reaction. None of the seven SNP showed any differences in the allelic or genotype frequencies between Ps patients and controls. Our study showed no significant association between the SNP in the genes encoding for RANK, OPG and RANKL with susceptibility of disease in Ps and PsA patients.
    The Journal of Dermatology 11/2010; 38(6):519-23. · 1.49 Impact Factor
  • Article: Age at onset in Huntington's disease: replication study on the associations of ADORA2A, HAP1 and OGG1.
    [show abstract] [hide abstract]
    ABSTRACT: In previous candidate gene studies, associations of the age at onset (AO) in Huntington disease (HD) have been reported with genetic variations in the genes encoding adenosinergic A(2A) receptor (ADORA2A), human huntingtin-associated protein-1 (HAP1) and the single base excision repair enzyme, 7,8-dihydro-8-oxoguanine-DNA glycosylase (OGG1). Here, we sought to replicate these associations in an established study population of 419 unrelated German HD patients. AO was defined as the age at which the first motor signs of HD appeared, motor AO (mAO). For 215 patients, also information about the first behavioural or cognitive signs of HD was available, so that we also tested for an association with the earliest AO. No association was found with OGG1. For HAP1, we found modest evidence for association with the same risk allele as in the original sample and mAO. Yet, we replicated the previously reported association between the original ADORA2A polymorphism when using the earliest AO. Additionally, we identified new associations in the same gene, thus further supporting the potential contribution of ADORA2A to the pathogenesis of HD.
    Neurogenetics 10/2010; 11(4):435-9. · 3.35 Impact Factor
  • Article: The future of ANCA-associated vasculitis.
    Julia U Holle, Stefan Wieczorek, Wolfgang L Gross
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    ABSTRACT: The introduction of cyclophosphamide for treatment and the detection of antineutrophil cytoplasmatic antibodies (ANCA) as a seromarker for ANCA-associated vasculitis (AAV) have been the most important milestones in the history of AAV. Nevertheless, there are still many issues to resolve to fully understand the pathogenesis of AAV and to improve patient outcomes. There is a need for diagnostic criteria; treatment strategies need further improvement to reduce the toxicity of conventional immunosuppressants such as cyclophosphamide. The elucidation of the genetic background in patients with AAV and the role of granulomatous lesions found in Wegener's granulomatosis are required to fully understand the pathophysiology of AAV.
    Rheumatic diseases clinics of North America 08/2010; 36(3):609-21. · 2.59 Impact Factor
  • Article: A functionally relevant IRF5 haplotype is associated with reduced risk to Wegener's granulomatosis.
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    ABSTRACT: Wegener's granulomatosis (WG), characterized by systemic vasculitis and granulomatous inflammation, is a rare chronic rheumatic condition potentially sharing some etiopathological principles with other autoimmune disorders, e.g., rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Several large association studies have identified genetic risk factors for RA and SLE. Thereof, we have evaluated the relevance of the most promising ones in WG. 22 single nucleotide polymorphisms (SNPs) within or in the vicinity of CCL21, CD40, CDK6, IL21, IL2RB, IRF5, KIF5A, KLF12, MMEL1, PRKCQ, STAT4, TNFAIP3, and TRAF1/C5 have been genotyped in >600 German WG cases and >800 matched controls. While most polymorphisms did not show suspicious effects on WG susceptibility, SNPs representing TNFAIP3 (rs6922466, p = 0.032, odds ratio (OR) 0.83, 95% confidence interval (CI) 0.7--0.98) and CDK6 (rs42041, p = 0.0201, OR 1.21, 95% CI 1.03-1.43) revealed nominally significant differences in allele distribution. The strongest association was detected for a functionally relevant four SNP haplotype of IRF5, which comprised a protective effect (p = 0.0000897, p (corrected) = 0.0012, OR 0.73, 95% CI 0.62-0.85) similar to those previously seen in RA and SLE. Thus, we suggest that WG, SLE, and RA share some, but not many, genetic risk factors, which supports models of partly overlapping etiopathological mechanisms in these disorders.
    Journal of Molecular Medicine 04/2010; 88(4):413-21. · 4.67 Impact Factor
  • Article: Mitochondrial haplogroup H correlates with ATP levels and age at onset in Huntington disease.
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    ABSTRACT: Mitochondrial dysfunction has been implicated in the pathogenesis of Huntington disease (HD), a primarily neurodegenerative disorder that results from an expansion in the polymorphic trinucleotide CAG tract in the HD gene. In order to evaluate whether mitochondrial DNA (mtDNA) variation contributes to HD phenotype we genotyped 13 single nucleotide polymorphisms (SNPs) that define the major European mtDNA haplogroups in 404 HD patients. Genotype-dependent functional effects on intracellular ATP concentrations were assessed in peripheral leukocytes. In patients carrying the most common haplogroup H (48.3%), we demonstrate a significantly lower age at onset (AO). In combination with PGC-1 alpha genotypes, 3.8% additional residual variance in HD AO can be explained. Intracellular ATP concentrations in HD patients carrying the cytochrome c oxidase subunit I (CO1) 7028C allele defining haplogroup H were significantly higher in comparison to non-H individuals (mean +/- SEM, 599 +/- 51.8 ng/ml, n = 14 vs. 457.5 +/- 40.4 ng/ml, p = 0.03, n = 9). In contrast, ATP concentrations in cells of HD patients independent from mtDNA haplogroup showed no significant differences in comparison to matched healthy controls. Our data suggest that an evolutionarily advantageous mitochondrial haplogroup is associated with functional mitochondrial alterations and may modify disease phenotype in the context of neurodegenerative conditions such as HD.
    Journal of Molecular Medicine 04/2010; 88(4):431-6. · 4.67 Impact Factor
  • Article: Genetic variations in genes encoding RANK, RANKL, and OPG in rheumatoid arthritis: a case-control study.
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    ABSTRACT: Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of the joints, which may lead to structural damage of the cartilage and bone. The receptor activator of nuclear factor-kappaB (RANK) and the osteoprotegerin (OPG) cascade system have been reported to be essential in osteoclastogenesis. Genetic variations in the genes coding for RANK, RANK ligand (RANKL), and OPG are thought to play roles in the susceptibility to RA. In our case-control study, genomic DNA was obtained from 534 patients with RA who fulfilled the American College of Rheumatology 1987 criteria and 516 healthy control blood donors (HC). We studied 7 single-nucleotide polymorphisms (SNP) in the genes of RANK (2 SNP: rs1805034, rs35211496), OPG (2 SNP: rs3102735, rs2073618), and RANKL (3 SNP: rs9533156, rs2277438, rs1054016) using TaqMan assay-guided polymerase chain reaction. Genotype and allelic frequencies comparing RA patients with HC were analyzed by chi-square test for 2 x 3 and 2 x 2 tables, respectively. Genotype distributions of the SNP rs35211496 in the RANK gene as well as the SNP rs2277438 in the RANKL gene differed significantly between patients with RA and HC. The frequency of the minor allele of rs9533156 of RANKL was significantly higher in patients with RA than in HC (OR 0.84, 95% CI 0.71-0.99, p = 0.047). Multivariate analysis adjusted to sex and investigating SNP demonstrated a significantly elevated risk for RA associated with the major allele in the RANK SNP rs35211496 (p = 0.0231) and with the minor allele in the RANKL SNP rs2277438 (p = 0.0092). No significantly increased risk was detected in the other SNP. The minor allele of the RANK SNP rs35211496 may be protective against RA, while the minor alleles of the RANKL SNP rs2277438 may increase susceptibility to RA.
    The Journal of Rheumatology 03/2010; 37(5):900-4. · 3.69 Impact Factor
  • Article: Contrasting association of a non-synonymous leptin receptor gene polymorphism with Wegener's granulomatosis and Churg-Strauss syndrome.
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    ABSTRACT: There is evidence that the leptin/ghrelin system is involved in T-cell regulation and plays a role in (auto)immune disorders such as SLE, RA and ANCA-associated vasculitides (AAVs). Here, we evaluate the genetic background of this system in WG. We screened variations in the genes encoding leptin, ghrelin and their receptors, the leptin receptor (LEPR) and the growth hormone secretagogue receptor (GHSR). Three single nucleotide polymorphisms (SNPs) in each gene region were analysed in 460 German WG cases and 878 ethnically matched healthy controls. A three-SNP haplotype of GHSR was significantly associated with WG [P = 0.0067; corrected P-value (P(c)) = 0.026; odds ratio (OR) = 1.30; 95% CI 1.08, 1.57], as was one non-synonymous SNP in LEPR (Lys656Asn, P = 0.0034; P(c) = 0.013; OR = 0.72; 95% CI 0.58, 0.90). These four SNPs were re-analysed in independent cohorts of 226 German WG cases and 519 controls. While the GHSR association was not confirmed, allele frequencies of the LEPR SNP were virtually identical to those from the initial cohorts. Analysis of this SNP in the combined WG and control panels revealed a significant association of the LEPR 656Lys allele with WG (P = 0.00032; P(c) = 0.0013; OR = 0.72; 95% CI 0.60, 0.86). Remarkably, the Lys656Asn SNP showed contrasting allele distribution in two cohorts of 108 and 88 German cases diagnosed with Churg-Strauss syndrome (CSS, combined P = 0.0067; OR = 1.41; 95% CI 1.10, 1.81), whereas identical allele frequencies were revealed when comparing British WG and microscopic polyangiitis cases. While GHSR has to be further evaluated, these data provide profound evidence for an association of the LEPR Lys656Asn SNP with AAV, resulting in opposing effects in WG and CSS.
    Rheumatology (Oxford, England) 02/2010; 49(5):907-14. · 4.24 Impact Factor
  • Article: Recent progress in the genetics of Wegener's granulomatosis and Churg-Strauss syndrome.
    Stefan Wieczorek, Julia U Holle, Jörg T Epplen
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    ABSTRACT: Recently, numerous studies have been performed to elucidate the genetic background of Wegener's granulomatosis and Churg-Strauss syndrome (CSS). Many of these investigations suffer from low statistical power, inconsistent case classification and other error-prone study designs. The majority of these findings has to be considered preliminary, if not spurious. We summarize the most important and robust findings. HLA-DPB1, the association of which with Wegener's granulomatosis has been discovered some years ago, is still the strongest and best replicated risk locus for this condition. Yet, no association is demonstrable for CSS, in which another HLA locus, HLA-DR, seems to be more important. Vice versa, a strong association with IL10 promotor polymorphisms was detected in CSS but not in a large Wegener's granulomatosis panel. Numerous other associations, including CTLA4, CD226 and copy number polymorphisms of FCGR3B still need further investigation, before reliable conclusions can be drawn. In order to be able to evaluate critically the genetic background of Wegener's granulomatosis and CSS future projects should take into account several aspects of study design. These preconditions include sufficient numbers of cases (i.e. statistical power) and a clear-cut classification of these cases, thus allowing differentiated analyses of certain disease subgroups.
    Current opinion in rheumatology 10/2009; 22(1):8-14. · 4.60 Impact Factor
  • Article: Granuloma formation in ANCA-associated vasculitides.
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    ABSTRACT: Granuloma formation is a key pathologic finding in two of the anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides: Wegener's granulomatosis (WG) and Churg-Strauss syndrome (CSS). So far, no animal models have been established convincingly reproducing both vasculitic and granulomatous features typical of WG and CSS. In biopsies, granulomatous lesions are found both at distant extravascular sites and in the vicinity of inflamed vessels, e.g. in the lung. Intriguingly, WG-granulomata appear to display features of tertiary lymphoid tissue. Cartilaginous and osseous destruction is caused by granulomatous inflammation invading adjacent tissues. Rhinosinusitis is regularly encountered in WG and CSS. Septal perforation, saddle nose deformity, middle and inner ear symptoms, and granulomatous invasion of the palate, orbita, meninges, or the pituitary gland may complicate WG. Both common (e.g. FCGR3B copy number) and distinct (e.g. HLA-DP, IL-10.2) genetic factors have been identified in AAV potentially favouring inflammation and autoimmunity. The HLA-DPB1/RING1/RXRB region constitutes a quantitative trait locus for ANCA-positive WG with the strongest association to be reported up to now. A profound alteration of the T-cell response including Th1 and Th17 responses, anomalously NK-receptor-expressing 'NK-like' T cells, and dysfunctional regulatory T cells could facilitate and sustain granuloma formation and autoimmunity.
    APMIS. Supplementum 06/2009;
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    Article: PGC-1alpha as modifier of onset age in Huntington disease.
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    ABSTRACT: Although there is a strong correlation between CAG repeat length and age at onset (AO) of motor symptoms, individual Huntington disease (HD) patients may differ dramatically in onset age and disease manifestations despite similar CAG repeat lengths. This has led to a search for genetic factors that influence AO. In order to identify such a genetic modifier, we analysed polymorphisms in the PGC-1alpha gene. Recent data indicate inhibition of PGC-1alpha function by mutant Htt supporting a link between transcriptional deregulation and mitochondrial dysfunction in HD. In > 400 HD patients, a polymorphism located within intron 2, a potential recombination hot spot, explains a small, but statistically significant, amount of the variability in AO. Our data suggest that PGC-1alpha has modifying effects on the pathogenic process in HD.
    Molecular Neurodegeneration 03/2009; 4:10. · 4.28 Impact Factor
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    Article: Genetic variability of RXRB, PPARA, and PPARG in Wegener's granulomatosis.
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    ABSTRACT: A major genomic region involved in Wegener's granulomatosis includes the gene for retinoid receptor beta (RXRB) which forms heterodimers with peroxisome proliferator-activated receptors (PPARs). It is unclear whether this association directly arises from the RXRB allele(s) or via a linked variation. In order to reveal any hitherto unknown and potentially disease-relevant variation of the RXRB gene, we have genotyped four tagging SNPs of this genomic region and have directly sequenced selected WG patients and controls representing disease-associated haplotypes. Additionally, we have genotyped 2 SNPs each in the genes for PPARα and PPARγ (PPARA and PPARG). Hence, we confirmed the strong association of the RXRB locus with WG but could not reveal any novel variation in RXRB. None of the PPARA and PPARG SNPs showed association with WG. Moreover, no epistatic effect was seen between RXRB and PPARA/PPARG alleles. These results do not support an etiopathological role of PPAR in WG. Analyses of further genes functionally linked to RXRB may provide additional data useful to evaluate the RXRB association found in WG.
    PPAR Research 02/2009; 2009:786781.
  • Article: Expanded HSAN4 phenotype associated with two novel mutations in NTRK1.
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    ABSTRACT: Hereditary sensory and autonomic neuropathy type IV (HSAN4) is a severe autosomal recessive disorder characterized by childhood onset of sensory and autonomic dysfunction leading to hyperthermia, recurrent infections and physical impairment due to complications of osteoarthritis. Cognitive impairment and aggressive behaviour is common. HSAN4 is caused by mutations in the NTRK1 gene coding for the tyrosine kinase receptor A. We present detailed description of a rare, mild HSAN4 phenotype associated with two novel NTRK1 mutations. This Swedish patient presents with an adult onset of painful Charcot arthropathy, prolonged wound healing, discrete polyneuropathy, hypohidrosis without further autonomic dysfunction and no cognitive affection.
    Neuromuscular Disorders 08/2008; 18(8):681-4. · 2.80 Impact Factor
  • Article: ASK1 and MAP2K6 as modifiers of age at onset in Huntington's disease.
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    ABSTRACT: Huntington's disease (HD) is an autosomal dominantly inherited neurodegenerative disease associated with abnormal expansions of a stretch of perfect CAG repeats in the HD gene. The number of repeat units is predictive for the age at onset (AO) of neurological symptoms. Part of the remaining variation in AO is attributed to modifier genes. In this study, genes involved in apoptosis were investigated as candidates for modulating AO in HD. A panel of 304 candidate genes was screened for allelic associations with motor AO via linked micro-satellite markers by pooling the DNAs of HD individuals from opposite ends of the AO distribution. After genotyping promising markers from the pooling experiment individually, markers revealed consolidated evidence for association in a candidate region comprising the genes MAP3K5 (ASK1)/PEX7 at 6q23.3 and in the gene MAP2K6 at 17q24.3. Fine-mapping of these candidate regions in a cohort of 250 Caucasian HD patients using single nucleotide polymorphism (SNP) markers delimitated the precise locations of association. Certain variations in an ASK1-PEX7 haplotype block explain 2.6% of additional variance in AO in our HD cohort. In males, 4.9% additional variance could be attributed to MAP2K6 genotype variations. Altogether, ASK1-PEX7 haplotypes and MAP2K2 genotype variations explain 6.3% additional variance in AO for HD. We hypothesise that sequence variations of ASK1 and MAP2K6 lead to partially sex-specific changes in the levels and/or phosphorylation states of p38 and p38-regulated proteins that might contribute to the observed delaying effects in the AO of HD.
    Journal of Molecular Medicine 05/2008; 86(4):485-90. · 4.67 Impact Factor