Objective To assess the exposure levels of heavy metals,including lead,arsenic,mercury,and cadmium,in the local population in Sichuan and Chongqing,China,to compare and analyze the differences in reference intervals(RIs)obtained from direct and indirect sampling methods,and to explore the interchangeability and limitations of these two sampling methods.Methods RIs were obtained by the direct sampling method and the indirect sampling method.In the direct sample method,the levels of blood arsenic,urinary cadmium,urinary mercury,and blood lead levels of 5562 healthy participants aged 22-50 years in Sichuan and Chongqing,China were measured by atomic absorption spectrometry and inductively coupled plasma-mass spectrometry.Using the human biomonitoring(HBM)data,we established RIs for the population by a nonparametric method.On the other hand,in the indirect sampling method,RIs were established via a nonparametric method based on data from the laboratory information system(LIS)of a local hospital after stratifying healthy individuals using a Gaussian mixture model(GMM).Comparative analysis of the RIs derived from the two sampling methods were then conducted.Results The RI for blood arsenic was 0.11-1.3 μmol/L.The RI for urinary cadmium was 0.51-2.80 μmol/mol creatine for adults aged 22 to under 43 years and 0.66-2.96 μmol/mol creatine for adults aged 43-50 years.The RI for urinary mercury was 0.12-1.10 μmol/mol creatine.The RI for blood lead was 14.00-47.00 pg/L for adults aged 22 to under 41 year,16.00-53.38 pg/L for males aged 41-50 year,and 15.00-51.02 pg/L for females aged 41-50 year.Most of the RIs established by the direct sampling method had a narrower range compared to those established by the indirect sampling method,and the RIs established by both sampling methods were partially biased.Conclusions The RIs for blood arsenic,urine cadmium,urine mercury,and blood lead in healthy individuals aged 22-50 years in Sichuan and Chongqing,China were established using both direct and indirect sampling methods,which contributes to a better understanding of environmental exposure to metals in the general population and provides a reference for metal poisoning.For data from the same lab,the GMM-based indirect sampling method demonstrated relatively consistent performance in establishing RIs compared with the direct sampling method.

Objective:To elucidate the clinical and genetic characteristics of PLA2G6-related parkinsonism. Methods:The clinical, imaging and genetic data of 6 patients with PLA2G6-related parkinsonism admitted to Peking Union Medical College Hospital from January 2015 to December 2022 were retrospectively collected and analyzed. The prognosis was followed up through phone call. Results:There were 3 male and 3 female patients, and the age of disease onset was (24.3±5.4) years. Phenotypically, 5 of them had dystonia-parkinsonism (DP) with obvious atrophy of cerebellum and 1 presented as early-onset Parkinson′s disease (EOPD) with no brain structural abnormality. Only 1 patient presented with abnormal brain iron deposition. All of the patients were partially responsive to levodopa. Three cases underwent levodopa challenge test with the objective levodopa responsiveness varied from 10.3% and 10.6% in 2 DP patients, to 77.0% in 1 EOPD patient. Levodopa-induced dyskinesias were present in 4 of them, and all appeared within the first year since the initiation of dopaminergic treatment. Two patients underwent bilateral deep brain stimulation (DBS) of subthalamic nucleus and globus pallidus internus respectively, albeit revealed poor outcome. Genetically, 8 PLA2G6 variants were identified. Two of them were found to be novel (c.1973A>G and exon2 heterozygous deletion), and the most frequent variant was the c.991G>T mutation which was detected in 4 patients. Conclusions:The phenotype of PLA2G6-related parkinsonism is complex. Cerebellar atrophy is a frequent magnetic resonance imaging feature. Levodopa responsiveness tends to depend on the clinical phenotype, and EOPD is better than DP. DBS might not be promising in DP patients with obvious cerebral atrophy. The c.991G>T mutation is the most frequent mutation, suggesting a common founder effect.

Objective To identify the mutations in Cu/Zn superoxide dismutase ( SOD1 ) gene in three Chinese kindreds with amyotrophic lateral sclerosis ( ALS), compare the genotypes with those found in other ethnic groups and to analyze the clinical characteristics.Methods The diagnosis of ALS met El Escorial ALS diagnostic criteria.Genomic DNA was extracted from peripheral blood in ALS patients using standard procedure.PCR amplifications of five exons of SOD1 were performed using primers as described in the previous publication.The PCR products were directly sequenced.Results A heterozygous mutation H46R was found in four affected members in a family with middle age onset and slowly progressive ALS.A heterozygous mutation of G72C was identified in a 20-year-old male who died of respiratory failure after two years of ALS.His father carried the same mutation without clinical phenotype.In the third family with 20affected members with middle age onset and rapidly progress, a mutation of E13V was identified in 5 affected subjects.Conclusions This study is the first large screening of SOD1 mutation in Chinese familiar ALS patients.H46R has previously been found only in Japanese and Pakistanis; this is the first report in Chinese, suggesting H46R may be specific to Asians.The family with mutation G72C presented decreased penetrance, therefore screening SOD1 mutation in sporadic cases and unaffected family members is necessary.E133V is the first reported mutation and needs more study to investigate its effect on the disease.

Objective Amyotrophic lateral sclerosis(ALS)is a progressive paralytic disorder resulting from the degeneration of upper and lower motor neurons.Sporadic ALS(SALS)accounm for majority of patients.ALS is a kind of complex disorder.There were several single nucleotide polymorphism (SNP)reported to be associated with SALS in recently published genome-wide association(GWA)study,but there are few data from Asia ALS population and no report focus on SNP which may associated with SALS of Chinese origin.Our study is to screen and add the SNPs related to the risks of SALs in Chinese.Methods Eighty-six individuals with SALS and 94 matched controls were recruited for our study and genomic DNA from blood samples was extracted.Genotypes were determined by a matrix assisted laser desorption/ionization time of flisht mass spectrometry based approach followed by association analysis. Results Individual genotype data for 8 SNPs,rs6700125,rs10260404, rs1942239,rs2279812,rs2405657,rs558889,rs6922711 and rs935 1470 in Chinese population showed no significant association with sporadic ALS.Combining genotype data from published GWA,rs1942239 gained in strength of allelic association(P value decreased to 9.07×10-5 from 1.48×10-4),and rs558889 deviated Hardy-Weinberg equilibrium at ALS case group which may be associated with susceptibility.Conclusions SNP rs1942239 and rs558889 may contribute to susceptibility of sporadic ALS in Chinese patient.The larger sample studies are warranted to confirm the association.

Objective To investigate whether the polymorphism of rs10260404 in DPP6 gene in Chinese Han origin is associated with sporadic amyotrophic lateral sclerosis (SALS). Methods The genomic DNA was extracted from the leukocytes of whole blood samples in 58 Chinese Han patients with SALS and 52 healthy controls. The asymmetric PCR was processed in the presence of an unlabeled probe that contained the rs10260404 locus. The product was genotyped on light scanner and some was confirmed with sequencing. Results Two single nucleotide polymorphism, rs10260404 that was reportedly consistently strongly associated with susceptibility to SALS in different populations of European and American ancestry, rs10260404 were genotyped, but not strongly associated with ALS in Chinese patients(SALS:C:12.94%,T:87.06%;health controls:C:10.58%,T:89.43%;χ2=0.29,OR=1.256,95%CI 0.549-2.872, P>0.05). Conclusion The rs10260404 is not associated with ALS susceptibility in Chinese people.