Prevalence and risk factors for dementia and mild cognitive impairment among older people in Southeast China: a community-based study.

BACKGROUND: With the aging population, the number of individuals with dementia in China is increasing rapidly. This community-based study aimed to investigate the prevalence and risk factors for dementia and mild cognitive impairment (MCI) among older adults in China. METHODS: In this study, 20,070 individuals aged ≥ 65 were recruited between January 1, 2022, and February 1, 2023, from ten communities in Xiamen City, China. We collected data on age, sex, level of education, and medical history, as well as global cognition and functional status. The prevalence of dementia and MCI was examined, and the risk factors for different groups were assessed. RESULTS: The overall prevalence of dementia and MCI was approximately 5.4% (95% confidence interval [CI], 5.1-5.7) and 7.7% (95% CI, 7.4-8.1), respectively. The results also indicated that dementia and MCI share similar risk factors, including older age, female sex, hypertension, and diabetes mellitus. Compared with individuals with no formal education, those with > 6 years of education had an odds ratio for MCI of 1.83 (95% CI, 1.49-2.25). We also found that only 5.5% of the positive participants chose to be referred to the hospital for further diagnosis and treatment during follow-up visits. CONCLUSIONS: This study estimated the prevalence and risk factors for dementia and MCI among individuals aged ≥ 65 years in Southeast China. These findings are crucial for preventing and managing dementia and MCI in China.

A genetic analysis of Chinese patients with early-onset Parkinson' s disease.

Genetic factors play an important role in early-onset Parkinson's disease (EOPD). The genetic spectrum of patients with EOPD varies widely among different ethnicities, with extensive investigations having been performed in Caucasian populations; however, research in Chinese populations remains limited. In this study, we performed multiplex ligation-dependent probe amplification assay and whole-exome sequencing in 15 unrelated Chinese EOPD patients with age of onset before 40 years. Among them, a patient carried compound heterozygous exon duplications in Parkin (exon 3 duplication and exon 4 duplication) (6.67 %) and two patients carried the homozygous pathogenic variant (p.D331Y) in PLA2G6 (13.33 %). Three novel variants in EIF4G1 (p.P1043S, p.R1505Q, and p.P266A) were identified and classified as uncertain significance. Additionally, a risk variant in GBA (p.L483P) was detected in one patient (6.67 %). PLA2G6 (13.33 %) was the most common causative gene among our EOPD patients. Furthermore, detailed clinical features were presented. Our results broaden the genetic spectrum and clinical phenotypic spectrum of EOPD patients.

A Pathogenic Variant p.Phe177Val in PSEN1 Causes Early-Onset Alzheimer's Disease in a Chinese Family.

Familial Alzheimer's disease (FAD) present as a positive family history of cognitive decline, with early onset and an autosomal dominant inheritance pattern. FAD is mainly caused by the mutations in the genes encoding for amyloid precursor protein (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2). In the present study, we identified a variant (c.529T > G, p.Phe177Val) in PSEN1 across three generations in a Chinese family with FAD using whole-exome sequencing. The mean age of onset was 39 years (range: 37 to 40 years) in this family. In cell transfection studies, the mutant PSEN1 protein carrying p.Phe177Val increased both the production of Aß42 and the ratio of Aß42 over Aß40, as compared to wild-type PSEN1. Our results confirm the pathogenicity of PSEN1 p.Phe177Val variant in FAD and broaden the clinical phenotype spectrum of FAD patients with PSEN1 p.Phe177Val variant.