Clonal hematopoiesis with DNMT3A mutation is associated with lower white matter hyperintensity volume.

Background: Clonal hematopoiesis of indeterminate potential (CHIP) increases the risk of cerebrovascular events, while its association with cerebral white matter hyperintensity (WMH) is undemonstrated. We evaluated the effect of CHIP and its major driving mutations on cerebral WMH severity.

Methods: From an institutional cohort of a routine health check-up program with a DNA repository database, subjects who were ≥50 years of age, with one or more cardiovascular risk factors but no central nervous system disorder, and performed brain MRI were included. Along with the presence of CHIP and its major driving mutations, clinical and laboratory data were obtained. WMH volume was measured in total, periventricular, and subcortical regions.

Results: Among the total 964 subjects, 160 subjects were classified as CHIP positive group. CHIP was most frequently associated with DNMT3A mutation (48.8%), followed by TET2 (11.9%) and ASXL1 (8.1%) mutations. Linear regression analysis adjusting for age, sex, and conventional cerebrovascular risk factors suggested that CHIP with DNMT3A mutation was associated with the lower log-transformed total WMH volume, unlike other CHIP mutations. When classified according to variant allele fraction (VAF) value of DNMT3A mutation, higher VAF classes were associated with the lower log-transformed total WMH and the lower log-transformed periventricular WMH volume, but not with the log-transformed subcortical WMH volumes.

Conclusions: Clonal hematopoiesis with DNMT3A mutation is quantitatively associated with a lower volume of cerebral WMH, especially in the periventricular region. CHIP with DNMT3A mutation might have a protective role in the endothelial pathomechanism of WMH.