Penetrance estimate of LRRK2 p.G2019S mutation in individuals of non-Ashkenazi Jewish ancestry

BACKGROUND

Penetrance estimates of the leucine-rich repeat kinase 2 (LRRK2) p.G2019S mutation for PD vary widely (24%-100%). The p.G2019S penetrance in individuals of Ashkenazi Jewish ancestry has been estimated as 25%, adjusted for multiple covariates. It is unknown whether penetrance varies among different ethnic groups. The objective of this study was to estimate the penetrance of p.G2019S in individuals of non-Ashkenazi Jewish ancestry and compare penetrance between Ashkenazi Jews and non-Ashkenazi Jews to age 80.

METHODS

The kin-cohort method was used to estimate penetrance in 474 first-degree relatives of 69 non-Ashkenazi Jewish LRRK2 p.G2019S carrier probands at 8 sites from the Michael J. Fox LRRK2 Cohort Consortium. An identical validated family history interview was administered to assess age at onset of PD, current age, or age at death for relatives in different ethnic groups at each site. Neurological examination and LRRK2 genotype of relatives were included when available.

RESULTS

Risk of PD in non-Ashkenazi Jewish relatives who carry a LRRK2 p.G2019S mutation was 42.5% (95% confidence interval [CI]: 26.3%-65.8%) to age 80, which is not significantly higher than the previously estimated 25% (95% CI: 16.7%-34.2%) in Ashkenazi Jewish carrier relatives. The penetrance of PD to age 80 in LRRK2 p.G2019S mutation carrier relatives was significantly higher than the noncarrier relatives, as seen in Ashkenazi Jewish relatives.

CONCLUSIONS

The similar penetrance of LRRK2 p.G2019S estimated in Ashkenazi Jewish carriers and non-Ashkenazi Jewish carriers confirms that p.G2019S penetrance is 25% to 42.5% at age 80 in all populations analyzed. © 2017 International Parkinson and Movement Disorder Society.

Higher frequency of certain cancers in LRRK2 G2019S mutation carriers with Parkinson disease: a pooled analysis

IMPORTANCE

Patients with Parkinson disease (PD) who harbor LRRK2 G2019S mutations may have increased risks of nonskin cancers. However, the results have been inconsistent across studies.

OBJECTIVES

To analyze pooled data from 5 centers to further examine the association between LRRK2 G2019S mutation and cancer among patients with PD and to explore factors that could explain discrepancies.

DESIGN, SETTING, AND PARTICIPANTS

Clinical, demographic, and genotyping data as well as cancer outcomes were pooled from 1549 patients with PD recruited across 5 movement disorders clinics located in Europe, Israel, and the United States. Associations between LRRK2 G2019S mutation and the outcomes were examined using mixed-effects logistic regression models to estimate odds ratios (ORs) and 95% CIs. Models were adjusted for age and ethnicity (Ashkenazi Jewish vs others) as fixed effects and study center as a random effect.

MAIN OUTCOMES AND MEASURES

All cancers combined, nonskin cancers, smoking-related cancers, hormone-related cancers, and other types of cancer.

RESULTS

The overall prevalence of the LRRK2 G2019S mutation was 11.4% among all patients with PD. Mutation carriers were younger at PD diagnosis and more likely to be women (53.1%) and of Ashkenazi Jewish descent (76.8%) in comparison with individuals who were not mutation carriers. The LRRK2 G2019S mutation carriers had statistically significant increased risks for nonskin cancers (OR, 1.62; 95% CI, 1.04-2.52), hormone-related cancers (OR, 1.87; 95% CI, 1.07-3.26) and breast cancer (OR, 2.34; 95% CI, 1.05-5.22) in comparison with noncarriers. There were no associations with other cancers. There were no major statistically significant differences in the results when the data were stratified by Ashkenazi Jewish ethnicity; however, there was some evidence of heterogeneity across centers.

CONCLUSIONS AND RELEVANCE

This multinational study from 5 centers demonstrates that LRRK2 G2019S mutation carriers have an overall increased risk of cancer, especially for hormone-related cancer and breast cancer in women. Larger prospective cohorts or family-based studies investigating associations between LRRK2 mutations and cancer among patients with PD are warranted to better understand the underlying genetic susceptibility between PD and hormone-related cancers.

Influence of the Reaction Temperature on the Nature of the Active and Deactivating Species During Methanol-to-Olefins Conversion over H-SAPO-34

The selectivity toward lower olefins during the methanol-to-olefins conversion over H-SAPO-34 at reaction temperatures between 573 and 773 K has been studied with a combination of operando UV-vis diffuse reflectance spectroscopy and online gas chromatography. It was found that the selectivity toward propylene increases in the temperature range of 573-623 K, while it decreases in the temperature range of 623-773 K. The high degree of incorporation of olefins, mainly propylene, into the hydrocarbon pool affects the product selectivity at lower reaction temperatures. The nature and dynamics of the active and deactivating hydrocarbon species with increasing reaction temperature were revealed by a non-negative matrix factorization of the time-resolved operando UV-vis diffuse reflectance spectra. The active hydrocarbon pool species consist of mainly highly methylated benzene carbocations at temperatures between 573 and 598 K, of both highly methylated benzene carbocations and methylated naphthalene carbocations at 623 K, and of only methylated naphthalene carbocations at temperatures between 673 and 773 K. The operando spectroscopy results suggest that the nature of the active species also influences the olefin selectivity. In fact, monoenylic and highly methylated benzene carbocations are more selective to the formation of propylene, whereas the formation of the group of low methylated benzene carbocations and methylated naphthalene carbocations at higher reaction temperatures (i.e., 673 and 773 K) favors the formation of ethylene. At reaction temperatures between 573 and 623 K, catalyst deactivation is caused by the gradual filling of the micropores with methylated naphthalene carbocations, while between 623 and 773 K the formation of neutral poly aromatics and phenanthrene/anthracene carbocations are mainly responsible for catalyst deactivation, their respective contribution increasing with increasing reaction temperature. Methanol pulse experiments at different temperatures demonstrate the dynamics between methylated benzene and methylated naphthalene carbocations. It was found that methylated naphthalene carbocations species are deactivating and block the micropores at low reaction temperatures, while acting as the active species at higher reaction temperatures, although they give rise to the formation of extended hydrocarbon deposits.

Inflammatory profile in LRRK2-associated prodromal and clinical PD

Background

There is evidence for a relevant role of inflammation in the pathogenesis of Parkinson’s disease (PD). Mutations in the LRRK2 gene represent the most frequent genetic cause for autosomal dominant PD. LRRK2 is highly expressed in macrophages and microglia suggesting an involvement in inflammatory pathways. The objectives are to test (1) whether idiopathic PD and LRRK2-associated PD share common inflammatory pathways or present distinct profiles and (2) whether non-manifesting LRRK2 mutation carriers present with similar aspects of inflammatory profiles as seen in PD-affected patients.

Methods

We assessed serum profiles of 23 immune-associated markers and the brain-derived neurotrophic factor in 534 individuals from the MJFF LRRK2 consortium.

Results

A large proportion of inflammatory markers were gender-dependent. Both PD-affected cohorts showed increased levels of the pro-inflammatory marker fatty-acid-binding protein. Additionally, idiopathic PD but not LRRK2-associated PD patients showed increased levels of the pro-inflammatory marker interleukin-12-p40 as well as the anti-inflammatory species interleukin-10, brain-derived neurotrophic factor, and stem cell factor. Non-manifesting LRRK2 mutation carriers including those with prodromal characteristics of PD presented with control-like inflammatory profiles.

Conclusions

Concomitant inflammation seems to be associated with idiopathic and LRRK2-associated PD. Identifying PD patients in whom inflammatory processes play a major role in their pathophysiology might offer a new therapeutic window at least for a subgroup of patients. Since non-manifesting LRRK2 mutation carriers with symptoms of the prodromal phase of PD did not show inflammatory profiles, activation of the immune system seems not an early event in the disease cascade.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0588-5) contains supplementary material, which is available to authorized users.

Inflammatory profile discriminates clinical subtypes in LRRK2-associated Parkinson's disease

BACKGROUND AND PURPOSE

The presentation of Parkinson's disease patients with mutations in the LRRK2 gene (PD_LRRK2 ) is highly variable, suggesting a strong influence of modifying factors. In this context, inflammation is a potential candidate inducing clinical subtypes.

METHODS

An extensive battery of peripheral inflammatory markers was measured in human serum in a multicentre cohort of 142 PD_LRRK2 patients from the MJFF LRRK2 Consortium, stratified by three different subtypes as recently proposed for idiopathic Parkinson's disease: diffuse/malignant, intermediate and mainly pure motor.

RESULTS

Patients classified as diffuse/malignant presented with the highest levels of the pro-inflammatory proteins interleukin 8 (IL-8), monocyte chemotactic protein 1 (MCP-1) and macrophage inflammatory protein 1-β (MIP-1-β) paralleled by high levels of the neurotrophic protein brain-derived neurotrophic factor (BDNF). It was also possible to distinguish the clinical subtypes based on their inflammatory profile by using discriminant and area under the receiver operating characteristic curve analysis.

CONCLUSIONS

Inflammation seems to be associated with the presence of a specific clinical subtype in PD_LRRK2 that is characterized by a broad and more severely affected spectrum of motor and non-motor symptoms. The pro-inflammatory metabolites IL-8, MCP-1 and MIP-1-β as well as BDNF are interesting candidates to be included in biomarker panels that aim to differentiate subtypes in PD_LRRK2 and predict progression.

Methanol-to-olefins process over zeolite catalysts with DDR topology: effect of composition and structural defects on catalytic performance

The effect of physicochemical properties on catalyst deactivation, overall olefin selectivity and ethylene/propylene ratio during the methanol-to-olefins (MTO) reaction is presented for two zeolites with the DDR topology, Sigma-1 and ZSM-58.

The ACMSD gene, involved in tryptophan metabolism, is mutated in a family with cortical myoclonus, epilepsy, and parkinsonism

Familial cortical myoclonic tremor and epilepsy is a phenotypically and genetically heterogeneous autosomal dominant disorder characterized by the presence of cortical myoclonic tremor and epilepsy that is often accompanied by additional neurological features. Despite the numerous familial studies performed and the number of loci identified, there is no gene associated with this syndrome. It is expected that through the application of novel genomic technologies, such as whole exome sequencing and whole genome sequencing, a substantial number of novel genes will come to light in the coming years. In this study, we describe the identification of two disease-segregating mutations in a large family featuring cortical myoclonic tremor with epilepsy and parkinsonism. Due to the previous association of ACMSD deficiency with the development of epileptic seizures, we concluded that the identified nonsense mutation in the ACMSD gene, which encodes for a critical enzyme of the kynurenine pathway of the tryptophan metabolism, is the disease-segregating mutation most likely to be responsible for the phenotype described in our family. This finding not only reveals the identification of the first gene associated with familial cortical myoclonic tremor and epilepsy but also discloses the kynurenine pathway as a potential therapeutic target for the treatment of this devastating syndrome.

KEY MESSAGE

ACMSD is mutated in a family with cortical myoclonus, epilepsy, and parkinsonism. ACMSD mutation contributes to the development of FCMTE QA accumulation is likely to play an important role in the pathogenesis of FCMTE. The kynurenine pathway as a potential drug target for the treatment of epilepsy.

Apolipoprotein E epsilon4 allele in familial and sporadic Parkinson's disease

Parkinson's disease (PD) is the second most common age-related neurodegenerative disease after Alzheimer's disease (AD). Common risk factors for both diseases have been explored to study potential etiologic interactions between these two neurodegenerative disorders. The APOE epsilon4 allele, previously associated with AD, has also been associated with risk of PD and with the presence of some clinical features in PD patients. However, the role of APOE epsilon4 allele in risk of PD remains unclear. We studied the distribution of APOE alleles in 276 unrelated familial and sporadic PD patients and in 212 controls. Patients and controls were classified by ethnicity. No genetic heterogeneity between Basques and people from other regions of Spain was found. No significant differences in APOE allele distribution between PD patients and controls were found; however, lower epsilon4 allele frequency was observed when the sporadic PD group was analyzed separately. By contrast, an increase in epsilon4 allele frequency was found in familial PD patients with cognitive decline. We conclude that the APOE epsilon4 allele may be associated with the risk of developing PD in isolated cases and that it is linked to the presence of cognitive decline in familial PD in our sample.

SORT1 Mutation Resulting in Sortilin Deficiency and p75(NTR) Upregulation in a Family With Essential Tremor

*These authors contributed equally to this work.

Essential tremor (ET) is the most prevalent movement disorder affecting millions of people in the United States. Although a positive family history is one of the most important risk factors for ET, the genetic causes of ET remain unknown. In this study, whole exome sequencing and subsequent approaches were performed in a family with an autosomal dominant form of early-onset ET. Functional analyses including mutagenesis, cell culture, gene expression, enzyme-linked immunosorbent, and apoptosis assays were also performed. A disease-segregating mutation (p.Gly171Ala), absent in normal population, was identified in the SORT1 gene. The p.Gly171Ala mutation was shown not only to impair the expression of its encoding protein sortilin but also the mRNA levels of its binding partner p75 neurotrophin receptor that is known to be implicated in brain injury, neuronal apoptosis, and neurotransmission.

SCN4A pore mutation pathogenetically contributes to autosomal dominant essential tremor and may increase susceptibility to epilepsy

Essential tremor (ET) is the most prevalent movement disorder, affecting millions of people in the USA. Although a positive family history is one of the most important risk factors for ET, the genetic causes of ET remain unknown. In an attempt to identify genetic causes for ET, we performed whole-exome sequencing analyses in a large Spanish family with ET, in which two patients also developed epilepsy. To further assess pathogenicity, site-directed mutagenesis, mouse and human brain expression analyses, and patch clamp techniques were performed. A disease-segregating mutation (p.Gly1537Ser) in the SCN4A gene was identified. Posterior functional analyses demonstrated that more rapid kinetics at near-threshold potentials altered ion selectivity and facilitated the conductance of both potassium and ammonium ions, which could contribute to tremor and increase susceptibility to epilepsy, respectively. In this report, for the first time, we associated the genetic variability of SCN4A with the development of essential tremor, which adds ET to the growing list of neurological channelopathies.

Cancer outcomes among Parkinson's disease patients with leucine rich repeat kinase 2 mutations, idiopathic Parkinson's disease patients, and nonaffected controls

BACKGROUND

Increased cancer risk has been reported in Parkinson's disease (PD) patients carrying the leucine rich repeat kinase 2 (LRRK2) G2019S mutation (LRRK2-PD) in comparison with idiopathic PD (IPD). It is unclear whether the elevated risk would be maintained when compared with unaffected controls.

METHODS

Cancer outcomes were compared among 257 LRRK2-PD patients, 712 IPD patients, and 218 controls recruited from 7 LRRK2 consortium centers using mixed-effects logistic regression. Data were then pooled with a previous study to examine cancer risk between 401 LRRK2-PD and 1946 IPD patients.

RESULTS

Although cancer prevalence was similar among LRRK2-PD patients (32.3%), IPD patients (27.5%), and controls (27.5%; P = 0.33), LRRK2-PD had increased risks of leukemia (odds ratio [OR] = 4.55; 95% confidence interval [CI], 1.46-10.61) and skin cancer (OR = 1.61; 95% CI, 1.09-2.37). In the pooled analysis, LRRK2-PD patients had also elevated risks of leukemia (OR = 9.84; 95% CI, 2.15-44.94) and colon cancer (OR = 2.34; 95% CI, 1.15-4.74) when compared with IPD patients.

CONCLUSIONS

The increased risks of leukemia as well as skin and colon cancers among LRRK2-PD patients suggest that LRRK2 mutations heighten risks of certain cancers. © 2019 International Parkinson and Movement Disorder Society.

UCP2 and mitochondrial haplogroups as a multiple sclerosis risk factor

In the actual scenario of the search for further genetic susceptibility factors, a recent paper noted an SNP in the UCP2 gene as a multiple sclerosis (MS) risk factor. UCP2 is a member of the mitochondrial proton transport family, which uncouples proton entry in the mitochondrial matrix from ATP synthesis. mtDNA haplogroups are also associated with ATP production, and are linked with mitochondrial proton transport. In this work, we studied the UCP2 SNP and the mitochondrial haplogroups distribution in a Spanish MS population, with a population sub-group of Basque-origin patients. Our results confirm the link between UCP2 SNP and MS, and show a slight relation between this SNP and mitochondrial haplogroups.

Cognitive dysfunction in Parkinson's disease related to the R1441G mutation in LRRK2

OBJECTIVE

The neuropsychological characteristics of patients with Parkinson's Disease (PD) associated with R1441G mutation in the LRRK2 gene (R1441G-PD) are not well known. The aim of this study was to examine the cognitive status and mood of R1441G-PD patients.

METHODS

Thirty patients with R1441G-PD were compared with thirty idiopathic PD (i-PD) patients who were matched by age, sex, education, disease onset age and duration, using a comprehensive battery of neuropsychological test, and considering the Movement Disorder Society (MDS) criteria for the diagnosis of Mild Cognitive Impairment (PD-MCI) and dementia (PD-Dementia).

RESULTS

The mean scores in the depression and anxiety scales were similar in the two groups. Depressive symptoms were detected in 31.8% of R1441G-PD and 25% of i-PD patients and anxiety symptoms were evident in 4.5% and 15%, respectively, but the differences were not significant. The only neuropsychological test on which there was a significantly worse performance in the R1441G-PD group was the Boston naming test but the difference became not significant when Bonferroni's correction was applied. The prevalence of PD-MCI was 30% in both R1441G-PD and i-PD, with no differences in the number and type of domains altered given that executive function, memory and attention were mainly affected. PD-Dementia was diagnosed in 13.3% (n = 4) of R1441G-PD and 26.7% (n = 8) of i-PD patients (difference was not significant).

CONCLUSION

In conclusion, significant differences were not detected between R1441G-PD and i-PD in cognitive, depression and anxiety scales, or PD-MCI and PD-Dementia prevalence, and the cognitive profile was identical in the two groups.

A More Homogeneous Phenotype in Parkinson's Disease Related to R1441G Mutation in the LRRK2 Gene

Parkinson's disease (PD) is characterized by a great clinical heterogeneity. Nevertheless, the biological drivers of this heterogeneity have not been completely elucidated and are likely to be complex, arising from interactions between genetic, epigenetic, and environmental factors. Despite this heterogeneity, the clinical patterns of monogenic forms of PD have usually maintained a good clinical correlation with each mutation once a sufficient number of patients have been studied. Mutations in LRRK2 are the most commonly known genetic cause of autosomal dominant PD known to date. Furthermore, recent genome-wide association studies have revealed variations in LRRK2 as significant risk factors also for the development of sporadic PD. The LRRK2-R1441G mutation is especially frequent in the population of Basque ascent based on a possible founder effect, being responsible for almost 50% of cases of familial PD in our region, with a high penetrance. Curiously, Lewy bodies, considered the neuropathological hallmark of PD, are absent in a significant subset of LRRK2-PD cases. Indeed, these cases appear to be associated with a less aggressive primarily pure motor phenotype. The aim of our research is to examine the clinical phenotype of R1441G-PD patients, more homogeneous when we compare it with sporadic PD patients or with patients carrying other LRRK2 mutations, and reflect on the value of the observed correlation in the genetic forms of PD. The clinical heterogeneity of PD leads us to think that there may be as many different diseases as the number of people affected. Undoubtedly, genetics constitutes a relevant key player, as it may significantly influence the phenotype, with differences according to the mutation within the same gene, and not only in familial PD but also in sporadic forms. Thus, extending our knowledge regarding genetic forms of PD implies an expansion of knowledge regarding sporadic forms, and this may be relevant due to the future therapeutic implications of all forms of PD.

Cognitive function in facioscapulohumeral dystrophy correlates with the molecular defect

Previous studies based on case descriptions and neuroradiological findings have suggested central nervous system (CNS) involvement in facioscapulohumeral dystrophy. The aim of this work is to explore the relationship between cognitive/personality pattern and the underlying molecular defect for this muscular dystrophy. We performed a wide-ranging neuropsychological assessment of 34 molecularly confirmed facioscapulohumeral dystrophy patients and 49 control subjects, all of whom also received the Millon-II Multiaxial Clinical Inventory (MCMI-II). Patients and controls show mild learning-level differences in the neuropsychological profile, and only the hysteriform scale is statistically higher in patients than controls. The patients' intelligence quotient (IQ) is related to the size of the deleted fragment but not to the degree of muscular impairment. The results of this study indicate a cut-off point and two distinct cognitive profiles in facioscapulohumeral dystrophy, depending on the patients' molecular defect: patients with a fragment size > 24 kb show a relatively normal cognitive pattern, whereas those with a fragment size < or = 24 kb show a significantly reduced IQ and difficulties with verbal function and visuo-constructive tasks. This work provides more evidence for the involvement of the CNS in facioscapulohumeral dystrophy and suggests that the fragment size should be taken into account in the clinical management of facioscapulohumeral dystrophy as it has a predictive value on the cognitive phenotype.

Combined Ex and In Situ Measurements Elucidate the Dynamics of Retained Species in ZSM-5 and SAPO-18 Catalysts Used in the Methanol-to-Olefins Reaction

The dynamics of the retained species on ZSM-5 and SAPO-18 catalysts are studied by using a combination of temperature-programmed desorption/oxidation, ex situ analysis, and in situ FTIR spectroscopic measurements over the entire conversion range, using fixed-bed and spectroscopic cell reactors, in continuous and discontinuous mode. The results point to the appropriateness of the combined methodologies to track the interconversion of active into deactivating species. A statistically relevant (supported by linear regression and multivariate analysis) association of the observations is found by using the different complementary methodologies. The kinetics of this interconversion depends on the initial conversion (tuned by acidity and space time) and microporous topology, and involve: (i) in the ZSM-5 catalysts, the diffusion of monocyclic aromatics toward the exterior of the zeolite to form coke, and (ii) in the SAPO-18 catalysts, the obstruction of the cavities by aromatics that grow into tetracyclic aromatic islands.

Cu boosting the collaborative effect of Ni and H+ in alloyed NiCu/saponite catalysts for hydrogenolysis of glycidol

The effect of copper on various acid saponite supported Ni-Cu bimetallic catalysts, prepared with different Ni : Cu ratios, was studied for the liquid phase hydrogenolysis of glycidol on a batch reactor at 393 and 453 K. Characterization of the catalysts showed that Ni and Cu are in close contact as the XRD measurements evidenced the formation of an alloy. H2 chemisorption results revealed that the measured metallic area progressively decreased with an increase in the wt% of copper. In the presence of high metal activity (higher Ni wt%), the formation of 1,2-propanediol (1,2-PD) outweighed, while acid activity led to the formation of dimerization and oligomerization products. The addition of Cu and the increase of the reaction temperature decreased the diol formation but boosted the 1,3-PD/1,2-PD ratio. This could be explained by an improvement of the collaborative effect between the metal Ni and the H+ of the saponite. Therefore, the presence of an appropriate amount of Cu allowed the control of the hydrogenation capacity of Ni and enhanced the collaborative effect of Ni and H+ favouring the formation of 1,3-propanediol with respect to 1,2-propanediol.

Defects of Nutrient Signaling and Autophagy in Neurodegeneration

Neurons are post-mitotic cells that allocate huge amounts of energy to the synthesis of new organelles and molecules, neurotransmission and to the maintenance of redox homeostasis. In neurons, autophagy is not only crucial to ensure organelle renewal but it is also essential to balance nutritional needs through the mobilization of internal energy stores. A delicate crosstalk between the pathways that sense nutritional status of the cell and the autophagic processes to recycle organelles and macronutrients is fundamental to guarantee the proper functioning of the neuron in times of energy scarcity. This review provides a detailed overview of the pathways and processes involved in the balance of cellular energy mediated by autophagy, which when defective, precipitate the neurodegenerative cascade of Parkinson's disease, frontotemporal dementia, amyotrophic lateral sclerosis or Alzheimer's disease.