CMDB: the comprehensive population genome variation database of China

Association between genetic predisposition and disease burden of stroke in China: a genetic epidemiological study

Background

Stroke ranks second worldwide and first in China as a leading cause of death and disability. It has a polygenic architecture and is influenced by environmental and lifestyle factors. However, it remains unknown as to whether and how much the genetic predisposition of stroke is associated with disease burden.

Methods

Allele frequency from the whole genome sequencing data in the Chinese Millionome Database of 141,418 individuals and trait-specific polygenic risk score models were applied to estimate the provincial genetic predisposition to stroke, stroke-related risk factors and stroke-related drug response. Disease burden including mortality, disability-adjusted life years (DALYs), years of life lost(YLLs), years lived with disability (YLDs) and prevalence in China was collected from the Global Burden Disease study. The association between stroke genetic predisposition and the epidemiological burden was assessed and then quantified in both regression-based models and machine learning-based models at a provincial resolution.

Findings

Among the 30 administrative divisions in China, the genetic predisposition of stroke was characterized by a north-higher-than-south gradient (p < 0.0001). Genetic predisposition to stroke, blood pressure, body mass index, and alcohol use were strongly intercorrelated (rho >0.6; p < 0.05 after Bonferroni correction for each comparison). Genetic risk imposed an independent effect of approximately 1-6% on mortality, DALYs and YLLs.

Interpretation

The distribution pattern of stroke genetic predisposition is different at a macroscopic level, and it subtly but significantly impacts the epidemiological burden. Further research is warranted to identify the detailed aetiology and potential translation into public health measures.

Funding

Beijing Municipal Science and Technology Commission (Z191100006619106), CAMS Innovation Fund for Medical Sciences (CAMS-I2M, 2023-I2M-1-001), the National High Level Hospital Clinical Research Funding (2022-GSP-GG-17), National Natural Science Foundation of China (32000398, 32171441 to X.J.), Natural Science Foundation of Guangdong Province, China (2017A030306026 to X.J.), and National Key R&D Program of China (2022YFC2502402).

Loss-of-Function of p21-Activated Kinase 2 Links BMP Signaling to Neural Tube Patterning Defects

Closure of the neural tube represents a highly complex and coordinated process, the failure of which constitutes common birth defects. The serine/threonine kinase p21-activated kinase 2 (PAK2) is a critical regulator of cytoskeleton dynamics; however, its role in the neurulation and pathogenesis of neural tube defects (NTDs) remains unclear. Here, the results show that Pak2^-/- mouse embryos fail to develop dorsolateral hinge points (DLHPs) and exhibit craniorachischisis, a severe phenotype of NTDs. Pak2 knockout activates BMP signaling that involves in vertebrate bone formation. Single-cell transcriptomes reveal abnormal differentiation trajectories and transcriptional events in Pak2^-/- mouse embryos during neural tube development. Two nonsynonymous and one recurrent splice-site mutations in the PAK2 gene are identified in five human NTD fetuses, which exhibit attenuated PAK2 expression and upregulated BMP signaling in the brain. Mechanistically, PAK2 regulates Smad9 phosphorylation to inhibit BMP signaling and ultimately induce DLHP formation. Depletion of pak2a in zebrafish induces defects in the neural tube, which are partially rescued by the overexpression of wild-type, but not mutant PAK2. The findings demonstrate the conserved role of PAK2 in neurulation in multiple vertebrate species, highlighting the molecular pathogenesis of PAK2 mutations in NTDs.