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Background: Fatal familial insomnia (FFI) is a rare autosomal-dominant inherited prion disease characterized clinically by severe sleep disorder, motor signs, dysautonomia and abnormal behaviour. FFI is caused by a missense mutation at codon 178 of the prion protein gene (PRNP). Our study is aimed to explore typical clinical and genetic features of two Chinese pedigrees with FFI and review the related literatures. Methods: Two FFI cases with family histories were recruited in our study. The main clinical features, genetic features and possible pathophysiologic mechanisms of these two FFI cases were analysed. Results: The foremost symptoms seemed to be sleep disturbances and psychosis. Progressive sympathetic symptoms, movement disturbances and memory loss were frequently observed as well. Electroencephalography (EEG) showed a minor slowing without periodic triphasic waves. Polysomnography (PSG) showed reduction in total sleep time and disturbance of sleep-related respiratory. Brain magnetic resonance imaging (MRI) did not reveal obvious abnormality. Genetic analysis disclosed the prion protein gene mutation at codon 178 (D178N), with methionine (Met) homozygosity at the polymorphic position 129 (Met129Met). Conclusions: The major clinical features of Chinese FFI are sleep dysfunction, psychiatric symptoms and sympathetic symptoms. Our patients have similar clinical characteristics as that of the typical FFI cases.

In the search for a highly active bulk material for the hydrogen evolution reaction (HER) under acidic conditions, we developed a simple solvothermal approach to synthesize Pd2B nanosheets supported on carbon, which achieves a low overpotential for the HER, 15.3 mV at 10 mA cm−2, a small Tafel slope of 22.5 mV dec−1 and a high exchange current density (j0) of 2.84 mA cm−2. The atomic structure evolution from Pd to Pd2B catalyst during synthesis is analyzed in detail via experimental and theoretical calculations, which shows that the slow insertion of B is assisted by the layer-by-layer fcc-to-hcp phase transition. Theoretical calculations further revealed that both the subsurface B and the lattice expansion after the hcp lattice formation play a key role to boost the HER activity. Since the Pd2B crystal is the global minimum in the Pd–B alloy, the success in the synthesis and demonstration of high HER activity paves the way towards further exploration of the catalytic performance for this stable metal boride material.

Background PINK1 (PTEN-induced putative kinase 1) gene is the causal gene for recessive familial type 6 of Parkinson’s disease (PARK6), which is an early-onset autosomal recessive inherited neurodegenerative disease. PINK1 has been reported to exert both autophosphorylation and phosphorylation activity, affecting cell damage under stress and other physiological responses. However, there has been no report on the identification of PINK1 autophosphorylation sites and their physiological functions. Methods (1) We adopted mass spectrometry assay to identify the autophosphorylation site of PINK1, and autoradiography assay was further conducted to confirm this result. (2) Kinase activity assay was used to compare the kinase activity of both Ser465 mutant PINK1 and disease-causing mutant PINK1. (3) We use Pulse-chase analysis to measure whether Ser465 may affect PINK1 degradation. (4) Immunocytochemistry staining was used to study the PINK1 subcellular localization and Parkin transition in subcellular level. Result In our study, we identified the 465th serine residue (Ser465) as one of the autophosphorylation sites in PINK1 protein. The inactivation of Ser465 can decrease the kinase activity of PINK1. Either dissipated or excessive Ser465 site phosphorylation of PINK1 can slow down its degradation. PINK1 autophosphorylation contributes to the transit of Parkin to mitochondria, and has no effect on its subcellular localization. PARK6 causal mutations, T313 M and R492X, display the same characteristics as Ser465A mutation PINK1 protein, such as decreasing PINK1 kinase activity and affecting its interaction with Parkin. Conclusion Ser465 was identified as one of the autophosphorylation sites of PINK1, which affected PINK1 kinase activity. In addition, Ser465 is involved in the degradation of PINK1 and the transit of Parkin to mitochondria. T313 M and R492X, two novel PARK6 mutations on Thr313 and Arg492, were similar to Ser465 mutation, including decreasing PINK1 phosphorylation activity and Parkin subcellular localization.

Two markers rs9652490 and rs11856808 both located in intron 3 of the LINGO1 gene have been nominated recently to be associated with essential tremor (ET). Although ET and Parkinson's disease (PD) are considered as different entities, they have many overlapping clinical and pathological features. We aimed to evaluate the role of rs9652490 and rs11856808 in the development of ET and PD. To this point, we sequenced the region involving the two markers in 109 ET cases, 425 sporadic Parkinson's disease (SPD) cases and 430 controls in Chinese population. After stratification by age, the rs9652490G allele suggested protective role in the early onset PD (EOPD, age at onset ≤50 years) group compared with age matched controls (OR = 0.56, 95% CI: 0.35–0.90, p = 0.015). No other significant association was found. We concluded that the two markers rs9652490 and rs11856808 were not strongly related to the development of ET or late onset SPD, but the rs9652490G allele might be a protective factor for EOPD in Chinese population.

It has been reported that some single-nucleotide polymorphisms (SNPs) are associated with the risk of Parkinson's disease (PD), but whether a combination of these SNPs would have a stronger association with PD than any individual SNP is unknown. Sixteen SNPs located in the 8 genes and/or loci (SNCA, LRRK2, MAPT, GBA, HLA-DR, BST1, PARK16, and PARK17) were analyzed in a Chinese cohort consisting of 1061 well-characterized PD patients and 1066 control subjects from Central South of Mainland China. We found that Rep1, rs356165, and rs11931074 in SNCA gene; G2385R in LRRK2 gene; rs4698412 in BST1 gene; rs1564282 in PARK17; and L444P in GBA gene were associated with PD with adjustment of sex and age (p < 0.05) in the analysis of 16 variants. PD risk increased when Rep1 and rs11931074, G2385R, rs1564282, rs4698412; rs11931074 and G2385R, rs1564282, rs4698412; G2385R and rs1564282, rs4698412; and rs1564282 and rs4698412 were combined for the association analysis. In addition, PD risk increased cumulatively with the increasing number of variants (odds ratio for carrying 3 variants, 3.494). In summary, we confirmed that Rep1, rs356165, and rs11931074 in SNCA gene, G2385R in LRRK2 gene, rs4698412 in BST1 gene, rs1564282 in PARK17, and L444P in GBA gene have an independent and combined significant association with PD. SNPs in these 4 genes have a cumulative effect with PD.

Autosomal dorminant Parkinson's disease (ADPD) has been associated with mutations in the SCNA , LRRK2 , UCHL1 , HtrA2 and GIGYF2 genes. We studied the prevalence of variants in all five genes in 12 Chinese unrelated families with ADPD and 4 families with both essential tremor (ET) and Parkinson's disease (PD) phenotypes using direct sequencing analysis. We found 27 variants in the LRRK2 gene, eight in GIGYF2 gene, three in the SCNA and UCHL1 gene respectively, in which five variants were novel. However, no pathogenic mutations in the five genes were found in these families. Our result indicated that SCNA , LRRK2 , UCHL1 , HtrA2 and GIGYF2 genes’ mutations might not be a main reason for Chinese ADPD.

Parkinson's disease (PD) is a common neurodegenerative disease resulting from complex interaction involving genetic and environmental risk factors on background of aging. In terms of genetic risk factors, recent studies provided a growing number of evidence for the idea that certain polymorphisms in familiar Parkinsonism genes may contribute to risk for sporadic PD in populations of specific ethnic backgrounds. To address this issue, a case-control study was conducted to determine the prevalence of LRRK2 Pro755Leu variant in 401 patients with sporadic PD and 398 unrelated healthy controls in Han population from mainland China. Heterozygous LRRK2 Pro755Leu variant was found in four patients and two healthy controls, but no statistical differences in genotypic or allelic frequencies between PD and control groups (genotype: P = 0.686; allele: P = 0.687) were detected. Furthermore, to evaluate its role in ethnic Chinese population, a meta-analysis was performed on Pro755Leu in population of Chinese ancestry throughout Asia. And it was detected at a similar frequency in PD and control cohort ( Z = 0.48, P = 0.63, odds ratio = 1.44, 95% CI: 0.32–6.40). Given these findings, it was quite reasonable to suppose that LRRK2 Pro755Leu variant rarely increased risk for PD in ethnic Chinese population in Asia.

The glucocerebrosidase (GBA) gene mutation is emerging as an important risk factor for Parkinson’s disease. We previously reported that the GBA gene L444P mutation is an important risk factor for PD in the Chinese population. The prevalence of this mutation in other neurodegenerative diseases and movement disorders remains completely unexplored in mainland China. In the present study, we extended the screening of GBA gene L444P mutation to Chinese patients with essential tremor (ET) and multiple system atrophy (MSA). We searched for the GBA gene L444P mutation in 109 patients with ET, 54 patients with MSA, and 657 controls from mainland China. None of the 109 patients with ET or 54 patients with MSA carried the GBA gene L444P mutation. Among the 657 controls, we found one L444P heterozygote. The difference in mutation frequencies between patients with ET or MSA and the control group was not statistically significant (chi-squared test, p = 1, respectively). The results suggest that the GBA gene L444P mutation may be not responsible for ET in mainland China. Whether the GBA gene L444P mutation modifies the risk for MSA deserves further study in larger samples.

An association between mutations in the glucocerebrosidase (GBA) gene and Parkinson's disease (PD) has been reported in several populations. We searched for four common GBA mutations (L444P, F213I, R353W, and N370S) in 402 Chinese PD patients and 413 age- and sex-matched controls. In the PD cohort, 11 patients were found carrying a heterozygous GBA mutation and all of them had the L444P mutation. Heterozygous GBA mutations were detected none in controls. The GBA gene L444P mutation was detected at a significantly higher frequency among PD patients (11/402 = 2.74%), when compared with the control group (0/413): P = 0.0007. To evaluate the possible role of the GBA gene L444P mutation in PD in Ashkenazi Jewish and non-Jewish populations, we conducted a meta-analysis on the topic. In the Chinese population, the GBA gene L444P mutation was detected at a significantly higher frequency among PD patients, when compared with the control group: Z = 3.83, P = 0.0001, OR = 8.42, confidence interval = 95%, 2.83-25.06. In the non-Jewish populations, the difference was obviously significant: Z = 5.76, P < 0.00001, OR = 8.82, confidence interval = 95%, 4.21-18.48. The results suggest that the GBA gene L444P mutation appears to be a risk factor for PD in Chinese population.