Sex Differences in Frequency, Severity, and Distribution of Cerebral Microbleeds

Fandler-Höfler S, Eppinger S, Ambler G et al. JAMA Netw Open. 2024 Oct 1;7(10):e2439571. doi: 10.1001/jamanetworkopen.2024.39571. PMID: 39405058

https://pubmed.ncbi.nlm.nih.gov/39405058/

Background and Objectives: Genome-wide association studies (GWASs) have only 2 loci associated with spontaneous intracerebral hemorrhage (ICH): APOE for lobar and 1q22 for nonlobar ICH. We aimed to discover new loci through an analysis that combines correlated traits (multi-trait analysis of GWAS [MTAG]) and explore a gene-based analysis, transcriptome-wide association study (TWAS), and proteome-wide association study (PWAS) to understand the biological mechanisms of spontaneous ICH providing potential therapeutic targets.

Methods: Weuse the published MTAG of ICH (patients with spontaneous intraparenchymal bleeding) and small-vessel ischemic stroke. For all ICH, lobar ICH, and nonlobar ICH, a pairwise MTAG combined ICH with traits related to cardiovascular risk factors, cerebrovascular diseases, or Alzheimer disease (AD). For the analysis, we assembled those traits with a genetic correlation ≥0.3. A new MTAGcombining multiple traits was performed with those traits whose pairwise MTAG yielded new GWAS-significant single nucleotide polymorphisms (SNPs), with a posterior-probability of model 3 (GWAS-pairwise) ≥0.6. We perform TWAS and PWAS that correlate the genetic component ofexpression or proteinlevels withthe genetic componen to fa trait. We use the ICH cohort from UK Biobank as replication.

Results: For all ICH (1,543 ICH, 1,711 controls), the mean age was 72 ± 2 in cases and 70 ± 2 in controls, and half of them were women. Replication cohort: 700 ICH and 399,717 controls. Novel loci were found only for all ICH (the trait containing lobar and nonlobar ICH), combining data of ICH and small vessel stroke, white matter hyperintensities volume, fractional anisotropy, mean diffusivity, and AD. We replicated 6 SNPs belonging to 2q33.2 (ICA1L, β = 0.20, SE = 0.03, p value = 8.91 × 10−12), 10q24.33 (OBFC1, β = −0.12, SE =0.02, p value = 1.67 ×10−8), 13q34 (COL4A2, β = 0.02, SE = 0.02, p value = 2.34 × 10−11), and 19q13.32 (APOC1, β =−0.19, SE =0.03, p value = 1.38 × 10−12; APOE, β = 0.21, SE = 0.03, p value = 2.70 × 10−11; PVRL2:CTB-129P6.4, β = 0.15, SE = 0.03, p value = 1.38 × 10−8); 2 genes (SH3PXD2A, Zscore = 4.83, p value = 6.67 × 10−7;andAPOC1, Z-score: = 5.11, p value = 1.60 × 10−7); and ICA1L transcript (Z-score = 6.8, p value = 9.1 × 10−12) and protein levels (Z-score = −5.8, p value = 6.7 × 10−9).

Funding: This work was supported by grants from the Institutode Salud CarlosIII (PI11/0176),Generaci´on Project,Maestro Project (PI18/01338), INVICTUS+ network, RICORSICTUS (RD21/0006/0006) together with Next-Generation EU funds that finance the actions of the Recovery and Resilience Mechanism,and the Epigenesis Project (Marat´ode TV3), FEDER funds, iBio Stroke project (AC19/00106).E. Muiño is supportedby a R´ıoHortega Contract (CM18/00198) from the Instituto de Salud Carlos III. E. Muiño is supported by the Juan Rod´es contract (JR23/00045) from Instituto de Salud Carlos III. C. Gallego-Fabrega is supported by a Sara Borrell Contract (CD20/00043) from Instituto de Salud Carlos III and Fondo Europeo de Desarrollo Regional (ISCIII-FEDER). M. Lled´os is supported by a PFIS Contract (Contratos Predoctorales de Formaci´on en Investigaci´on en Salud) from the Instituto de Salud Carlos III (FI19/00309). I. Fern´andez-Cadenas (CP12/03298) is supported by a research contract from Miguel Servet Program from the Instituto de Salud Carlos III.