Parkinsonism and Anderson Fabry's disease: a case report

We describe and present a videotape of a 57-year-old woman admitted to our Neurological Clinic at 46 years of age due to extrapyramidal manifestations suggesting Parkinson's disease (PD) and with a brain magnetic resonance imaging scan showing multi-infarctual leukoencephalopathy. Various investigations led to the diagnosis of Anderson Fabry's disease (AFD). We discuss the possibility of correlation between the patient's parkinsonism and AFD.

Wld(S) mice are protected against the Parkinsonian mimetic MPTP

The progressive loss of the nigrostriatal pathway is a distinguishing feature of Parkinson's disease. Because terminal field loss appears to precede cell body loss, we tested whether the mouse mutant Wld(S), which delays axonal degeneration in a variety of disorders, would ameliorate nigrostriatal degeneration following treatment with the Parkinsonian mimetic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The present findings show that the Wld(S) gene product enhances survival, prevents nigrostriatal axon degeneration, and attenuates neurotransmitter loss but does not rescue cell bodies. As MPTP is thought to impair mitochondrial energy production, these data suggest that disease pathology due to metabolic dysfunction could be improved by the Wld(S) gene product. These results suggest new therapeutic avenues for Parkinson's disease.

Phosphatidylinositol Transfer Protein Expression Altered by Aging and Parkinson Disease

1. Phosphatidylinositol transfer proteins (PI-TP) are responsible for the transport of phosphatidylinositol (PI) and other phospholipids from endoplasmic reticulum to the other membranes and indirectly for lipid mediated signaling. Till now little is known about PI-TPs in brain aging and neurodegeneration. The aim of this study was to investigate expression of PI-TP in the brain during aging and in animal's model of Parkinson disease (PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Moreover, in vitro, effect of 1-methyl-4-phenyl-pyridine cation (MPP(+)) on PI-TP, tyrosine hydroxylase (TH) protein level, and viability of cells was investigated. 2. Wistar rats 4, 24, and 36 months old and C57/BL mice and rat pheochromocytoma (PC12) cell line were used for the studies. Mice C57/BL received three injections of MPTP in saline at 2 h intervals in a total dose of 40 mg/kg and then after 3, 7, and 14 days they were used for the investigation. PC12 cells were treated with increasing concentration (50-300 microM) of MPP(+) for 24 h at 37 degrees C. The level of PI-TP(alpha and beta) and TH were determined using Western Blot analysis. 3. Our data indicated that PI-TP(alpha and beta) level decreased in brain of 36 months old rat by 20% comparing to the control value (4 months old). In animal's model of PD, PI-TP(alpha and beta) level was significantly lower by 85, 69, 64% in striatum at 3, 7, and 14 days after MPTP injection, respectively, compared to the control value. MPP(+) decreased PI-TP(alpha and beta), TH expression, and viability of PC12 cells in a dose-dependent manner. H(2)O(2), menadione, and NO donor significantly decreased the PI-TP level and viability of PC12 cells. 4. Our results indicate the lower protein expression of PI-TP(alpha and beta) in aged brain and in PD and suggest that oxidative stress may be responsible for the alteration of PI-TP.

Morphological basis for the spectrum of clinical deficits in spinocerebellar ataxia 17 (SCA17)

Spinocerebellar ataxia 17 (SCA17) is a rare genetic disorder characterized by cerebellar, extrapyramidal, pyramidal as well as psychiatric signs. The pathoanatomical basis of this disorder is still not well known. A total of 12 patients and 12 age- and sex-matched controls were examined by in vivo MRI voxel-based morphometry (VBM). Besides general patterns of disease-related brain atrophy, characteristic syndrome-related morphological changes in SCA17 patients were studied. In comparison with normal controls, SCA17 patients showed a pattern of degeneration of the grey matter centred around mesial cerebellar structures, occipito-parietal structures, the anterior putamen bilaterally, the thalamus and other parts of the motor network, reflecting the cerebellar, pyramidal and extrapyramidal signs. A correlation analysis revealed a clear association between the clinical cerebellar, extrapyramidal and psychiatric scores and degeneration in specific areas. Two degeneration patterns were found as follows: regarding motor dysfunction, atrophy of the grey matter involved mainly the cerebellum and other motor networks, in particular the basal ganglia. In contrast, correlations with psychiatric scores revealed grey matter degeneration patterns in the frontal and temporal lobe, the cuneus and cingulum. Most interestingly, there was a highly significant correlation between the clinical Mini-Mental State Examination scores and atrophy of the nucleus accumbens, probably accounting for the leading psychiatric signs.

[Exon rearrangement analysis of parkin gene in patients with isolated early-onset parkinsonism using semi-quantitative PCR]

OBJECTIVE

To investigate the value of fluorescence semi-quantitative PCR in analysis of the exon rearrangement of parkin gene in Chinese patients with isolated early-onset parkinsonism (EOP).

METHODS

fluorescence semi-quantitative PCR was used to analyze the exon rearrangements of parkin gene in 61 isolated patients with EOP.

RESULTS

Exon deletions in parkin gene were found in 4 of the 61 isolated patients with EOP. One of them failed to show the PCR product of exon 4 and had homozygous deletions of exon 4. The normalized ratios (NRs) of exon 2, exon 3, and exon 4 of the other 3 patients were 0.47, 0.52, and 0.49 respectively, showing that they had heterozygous deletions of exon 2, 3, and 4 respectively. No exon multiplication was found in this study.

CONCLUSION

Exon rearrangement of parkin gene exists in Chinese patients with isolated EOP.

Size bias of fragile X premutation alleles in late-onset movement disorders

BACKGROUND

Fragile X-associated tremor/ataxia syndrome (FXTAS), caused by premutation expansions (55-200 CGG repeats) of the FMR1 gene, shares clinical features with other movement disorders, particularly in the domains of gait ataxia, intention tremor and parkinsonism. However, the prevalence of FXTAS within other diagnostic categories is not well defined.

METHODS

A meta-analysis was conducted of all published (n = 14) genetic screens for expanded FMR1 alleles to assess the prevalence and CGG-repeat size bias of FMR1 premutation alleles in those populations.

RESULTS

In men with late-onset cerebellar ataxia, the prevalence of premutation alleles (1.5%; 16/1049) was 13 times greater than expected based on its prevalence in the general population (2%; 16/818 for age of onset >50 years; odds ratio 12.4; 95% confidence interval 1.6 to 93.5). Meta-analysis of CGG-repeat data for screened patients with premutation alleles shows a shift to larger repeat size than in the general population (p<0.001). 86% (19/22) of premutation alleles were larger than 70 repeats in the patients screened, whereas only approximately 22% of premutation alleles are larger than 70 repeats in the general population.

CONCLUSIONS

Expanded FMR1 alleles contribute to cases of late-onset sporadic cerebellar ataxia, suggesting that FMR1 genetic testing should be carried out in such cases. The biased distribution of FMR1 allele sizes has substantial implications for genetic counselling of carriers with smaller alleles who are at a low risk of developing FXTAS, and suggests that the estimated prevalence of FXTAS among men >50 years of age in the general population may be two to threefold lower than the initial figure of 1 in 3000.

Attenuation of MPTP-induced neurotoxicity and locomotor dysfunction in Nucling-deficient mice via suppression of the apoptosome pathway

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity is one of the experimental models most commonly used to study the pathogenesis of Parkinson's disease (PD). Although the biochemical mechanisms underlying the cell death induced by MPTP remain to be clarified, it has been found that the mitochondrial apoptotic signaling pathway plays an important role in the neurotoxicity of MPTP. Nucling is a novel type of apoptosis-associated molecule, essential for cytochrome c, apoptosis protease activating factor 1 (Apaf-1), pro-caspase-9 apoptosome induction and caspase-9 activation following pro-apoptotic stress. Here we found that Nucling-deficient mice treated with MPTP did not exhibit locomotor dysfunction in an open-field test. The substantia nigra dopaminergic neurons of Nucling-deficient mice were resistant to the damaging effects of the neurotoxin MPTP. Up-regulated expression of apoptosome was attenuated in Nucling-deficient mice treated with MPTP. These results indicate an important role for Nucling in MPTP-induced neuronal degeneration and suggest that the suppression of Nucling would be of therapeutic benefit for the treatment of neurodegeneration in PD.

Detection of compound heterozygous deletions in the parkin gene of fibroblasts in patients with autosomal recessive hereditary parkinsonism (PARK2)

Mutations in the parkin gene are a common cause of autosomal recessive, juvenile or early onset parkinsonism (PARK2). In this report, we use RT-PCR to detect compound heterozygous deletions of the parkin gene in fibroblasts from two cases of middle age-onset familial parkinsonism with lower extremities-dominant resting tremor and mild cogwheel rigidity. Although exonic amplification of the parkin gene showed a deletional mutation of exon 3-4, their family histories suggested that the deletional mutations were a compound heterozygous abnormality of discrete origin. Immunoblotting demonstrated that abundant Parkin protein was expressed in fibroblasts, but little expression was detected in lymphocytes. RT-PCR using RNA isolated from the patients' fibroblasts indicated a parkin mutation in this family that consisted of compound heterozygous deletions (del exon3-4/del exon3-5). These results suggest that RT-PCR using the patients' fibroblasts may be helpful for the detection of compound heterozygous abnormalities in the parkin gene.

Mutations Phe785Leu and Thr618Met in Na+,K+-ATPase, associated with familial rapid-onset dystonia parkinsonism, interfere with Na+ interaction by distinct mechanisms

The Na(+),K(+)-ATPase plays key roles in brain function. Recently, missense mutations in the Na(+),K(+)-ATPase were found associated with familial rapid-onset dystonia parkinsonism (FRDP). Here, we have characterized the functional consequences of FRDP mutations Phe785Leu and Thr618Met. Both mutations lead to functionally altered, but active, Na(+),K(+)-pumps, that display reduced apparent affinity for cytoplasmic Na(+), but the underlying mechanism differs between the mutants. In Phe785Leu, the interaction of the E(1) form with Na(+) is defective, and the E(1)-E(2) equilibrium is not displaced. In Thr618Met, the Na(+) affinity is reduced because of displacement of the conformational equilibrium in favor of the K(+)-occluded E(2)(K(2)) form. In both mutants, K(+) interaction at the external activating sites of the E(2)P phosphoenzyme is normal. The change of cellular Na(+) homeostasis is likely a major factor contributing to the development of FRDP in patients carrying the Phe785Leu or Thr618Met mutation. Phe785Leu moreover interferes with Na(+) interaction on the extracellular side and reduces the affinity for ouabain significantly. Analysis of two additional Phe(785) mutants, Phe785Leu/Leu786Phe and Phe785Tyr, demonstrated that the aromatic function of the side chain, as well as its exact position, is critical for Na(+) and ouabain binding. The effects of substituting Phe(785) could be explained by structural modeling, demonstrating that Phe(785) participates in a hydrophobic network between three transmembrane segments. Thr(618) is located in the cytoplasmic part of the molecule near the catalytic site, and the structural modeling indicates that the Thr618Met mutation interferes with the bonding pattern in the catalytic site in the E(1) form, thereby destabilizing E(1) relative to E(2)(K(2)).

Recessive Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disease caused by loss of dopaminergic neurons in the substantia nigra pars compacta. Although the etiology of PD remains unclear, it is now clear that genetic factors contribute to the pathogenesis of the disease. Recently, several causative genes have been identified in monogenic forms of PD. Accumulating evidence indicates that their gene products play important roles in mitochondrial function, oxidative stress response, and the ubiquitin-proteasome system, which are also implicated in sporadic PD, suggesting that these gene products share a common pathway to nigral degeneration in both familial and sporadic PD. Here, we review recent advances in knowledge about genes associated with recessive PD, including parkin, PINK1, and DJ-1.

Phenotypic Commonalities in Familial and Sporadic Parkinson Disease

BACKGROUND

Parkinson disease (PD) is a clinically well-documented neurodegenerative disorder. However, the mechanism or mechanisms of its phenotypic expressions are still unknown.

OBJECTIVE

To compare phenotypes by examining demographic and clinical features of patients with familial PD and sporadic PD and with or without a family history of PD.

DESIGN

Historical review of patients with sporadic PD in clinic-based samples and individual patients diagnosed with PD from families whose linkage to mutations or loci has been identified.

SETTING

Movement disorder clinic in a referral center.

PATIENTS

A total of 1277 patients with sporadic PD and 40 patients with familial PD.

MAIN OUTCOME MEASURES

Clinical features, including distribution by sex, initial motor symptom, location of initial motor symptom, and frequency of asymmetric motor symptoms.

RESULTS

Despite different etiologic backgrounds, both familial and sporadic PD exhibited several interesting commonalities, including a higher incidence in men, tremor as the initial motor symptom (predominantly involving the upper extremities), and asymmetric parkinsonism during disease course.

CONCLUSIONS

The increased incidence of parkinsonism in men with familial PD suggests that the sex disparity is more likely the result of a protective effect against development of PD in women than of an increased risk in men that is associated with environmental factors. Phenotypic similarity among familial and sporadic PD indicates that a similar topographic distribution of the nigrostriatal lesion exists in patients with either form of PD regardless of apparent genetic influence.

BDNF genetic variants are associated with onset age of familial Parkinson disease: GenePD Study

Brain-derived neurotrophic factor (BDNF) stimulates neuronal growth and protects nigral dopamine neurons in animal models of Parkinson disease (PD). Therefore, BDNF is a candidate gene for PD. The authors investigated five single-nucleotide polymorphisms in 597 cases of familial PD. Homozygosity for the rare allele of the functional BDNF G196A (Val66Met) variant was associated with a 5.3-year older onset age (p = 0.0001). These findings suggest that BDNF may influence PD onset age.

[Animal models of parkinsonism]

Research into the pathophysiology of Parkinson's disease has been rapidly advanced by the development of animal models. Initial models were developed by using toxins that specifically targeted dopamine neurons, the most successful of which used 6-hydroxydopamine in rats and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in mice and primates. Their combination with specific striatal toxins, such as quinolinic acid or 3-nitropropionic acid, has led to the development of experimental models replicating the salient pathological and clinical features of multiple system atrophy of the striatonigral degeneration subtype both in rodents and primates. More recently, the identification of alpha-synuclein gene mutations in rare familial cases of Parkinson's disease has led to the development of alpha-synuclein knock-out and transgenic animals. We conclude that the use and improvement of both phenotypic and genetic models can significantly speed progress toward understanding the pathophysiology of these devastating diseases and finding innovative cures.

DJ-1 mutations and parkinsonism-dementia-amyotrophic lateral sclerosis complex

DJ-1 gene mutations have been found to cause early-onset Parkinson's disease. We report a family from southern Italy with three brothers affected by early-onset parkinsonism, dementia, and amyotrophic lateral sclerosis. Molecular analysis of the DJ-1 gene in two living patients showed a novel homozygous mutation in exon 7 (E163K) and a new homozygous mutation (g.168_185dup) in the promoter region of the gene. Both mutations cosegregated with the disease and were detected in a heterozygous state in the patients' mother and their healthy siblings. Our findings expand the spectrum of clinical presentations associated with mutations in DJ-1 gene.

Implications of Genetics on the Diagnosis and Care of Patients With Parkinson Disease

The identification of several monogenic forms has established Parkinson disease (PD) as a movement disorder with a considerable genetic origin in at least a subset of patients. Four of the known forms, Parkin-, PINK1 (PTEN-induced putative kinase 1)-, DJ1-, and LRRK2 (leucine-rich repeat kinase 2)-linked PD, may present clinically as "idiopathic PD" and account for at least 1% of all cases of PD. However, all known monogenic forms combined explain about only 20% of early-onset PD and less than 3% of late-onset PD at best. Although the individual clinical course cannot be predicted, overall, many cases of genetic PD will progress more slowly and respond better to treatment than patients without mutations. Genetic testing frequently yields inconclusive results, is expensive, and should be used for diagnostic purposes only after careful consideration in selected cases at specialty centers. While genetic findings have greatly advanced our understanding of the pathophysiology of PD, we are faced with many novel challenges. These include the definition of the phenotypic and genotypic spectrum of the monogenic forms, a revised terminology and classification of parkinsonian syndromes, identification of genetic susceptibility factors, and development of guidelines for genetic testing and of new treatment options for PD.

Kufor Rakeb disease: autosomal recessive, levodopa-responsive parkinsonism with pyramidal degeneration, supranuclear gaze palsy, and dementia

Kufor Rakeb disease is an autosomal recessive disorder characterized by subacute, juvenile-onset, levodopa-responsive parkinsonism, pyramidal signs, dementia, and a supranuclear gaze palsy. It was originally described more than a decade ago, and linkage analysis identified a locus on chromosome 1p36 that was previously assigned PARK9. We have further characterized the clinical picture and specifically re-assessed the response to levodopa in the original family, in the northern highlands of Jordan. In the 4 surviving patients, there has been a narrowing of the therapeutic window for levodopa with the emergence of peak-dose dyskinesias with increased spasticity and cognitive decline. Several new features were identified, including facial-faucial-finger mini-myoclonus, visual hallucinations, and oculogyric dystonic spasms.

Brain-derived neurotrophic factor is required for the establishment of the proper number of dopaminergic neurons in the substantia nigra pars compacta

Brain-derived neurotrophic factor (BDNF) has been implicated in regulating neuronal survival, differentiation, and synaptic plasticity. Reduced expression of BDNF within the substantia nigra accompanies the deterioration of dopaminergic neurons in Parkinson's disease (PD) patients. Analysis of the effects of long-term BDNF absence from the CNS has been difficult because of the early postnatal lethality of BDNF-/- mice. Mice with a floxed BDNF allele were bred with Wnt1-Cre mice to generate Wnt-BDNF(KO) mice that lack BDNF from the midbrain-hindbrain (MHB). These mice are viable but exhibit hindlimb clutching and poor rotarod performance. Tyrosine hydroxylase (TH)-positive neuron numbers in the substantia nigra pars compacta (SNC) were estimated using stereological methods, revealing a persistent approximately 23% reduction of these cells at postnatal day 21 (P21) in Wnt-BDNF(KO) mice compared with controls. The diminishment of TH-expressing neurons was present at birth and continued through P120. This deficit appears selective for the dopaminergic population, because at P21, total neuron number within the SNC, defined as neuronal nuclei protein-positive cells, was not significantly reduced. Interestingly, and similar to observations in PD patients, SNC neuron subpopulations are not equally affected. Calbindin- and calretinin-expressing SNC populations show no significant difference between Wnt-BDNF(KO) mice and controls. Thus, BDNF depletion from the MHB selectively leads to reduced TH expression in a subpopulation of neurons, but it remains unclear whether these cells are lost.

[Genotype and phenotype analyses of three families with autosomal recessive juvenile parkinsonism]

OBJECTIVE

To investigate the gene mutations and the clinical features of Chinese patients with autosomal recessive juvenile parkinsonism(AR-JP).

METHODS

the polymerase chain reaction (PCR), DNA sequence analysis, and restriction enzyme digestion analysis were applied to check parkin gene mutations of 15 index patients from 15 families with AR-JP.

RESULTS

Three families were detected to have parkin mutations. Two of them had heterozygous deletion mutations (202-203 del AG in exon 2, 1069-1074 del GTGTCC in exon 9) and another of them carried a heterozygous missense mutation [1422(T-->C) in exon 12]. Two of the mutations [1069-1074delGTGTCC and 1422(T-->C)] were not reported previously. There were six patients in the three families. Mean age at onset was 25.2+/-5.7 years, ranging from 18 to 31 years. The symptoms were under slow progression, diurnal fluctuation with sleep benefit, and hyperreflexia were relatively prominent. Response to levodopa was satisfactory.

CONCLUSION

There are parkin mutations happened in Chinese patients with AR-JP. Patients with parkin mutations have distinct clinical features besides the common clinical features of Parkinson's disease.

The sepiapterin reductase gene region reveals association in the PARK3 locus: analysis of familial and sporadic Parkinson's disease in European populations

BACKGROUND

Parkinson's disease is a genetically complex disease with mixed mode of inheritance. Recently, a haplotype across the sepiapterin reductase (SPR) gene, which is located in the PARK3 linkage region, was shown to modulate age of onset of Parkinson's disease in sibships from North America.

OBJECTIVE

To make a thorough assessment of the SPR gene region in sporadic Parkinson's disease.

METHODS

A linkage study in 122 European sibship families with five microsatellite and 17 single nucleotide polymorphism (SNP) markers in and around the SPR gene region, and an association analysis in 340 sporadic cases of Parkinson's disease and 680 control subjects from Germany with 40 SNPs. Linkage was evaluated by non-parametric linkage scores and genotypic or haplotype association was tested by regression analysis, assuming different risk effect models.

RESULTS

Significant LOD scores between 2 and 3 were obtained at the two SPR-flanking markers D2S2110 and D2S1394 and seven SNP markers around the SPR gene. We found the previously reported promoter SNP rs1876487 also significantly associated with age of onset in our sib pair families (p-value 0.02). One strong linkage disequilibrium (LD) block of 45 kb including the entire SPR gene was observed. Within this LD block all 14 inter-correlated SNPs were significantly associated with Parkinson's disease affection status (p-value 0.004).

CONCLUSIONS

DNA polymorphisms in a highly intercorrelated LD block, which includes the SPR gene, appear to be associated with both sporadic and familial Parkinson's disease. This confirms a previous study showing that SPR potentially modulates the onset of or risk for Parkinson's disease.