Analysis of dementia-related gene variants in APOE ε4 noncarrying Korean patients with early-onset Alzheimer's disease.

There is a genetic overlap among various neurodegenerative diseases that cause dementia. We analyzed dementia-related gene variants in 60 apolipoprotein E ε4 non-carrying Korean patients with early-onset Alzheimer's disease. Thirty-one dementia-related genes were screened by exome sequencing. Among the 60 patients, three likely pathogenic variants (LPVs) and 1 variant of uncertain significance (VUS) were identified in PSEN1. In addition, two LPVs in TYROBP (c.141del) and PINK1 (c.1220G>A) and 17 VUS were found in other dementia-causing genes. Two variants in SORL1 and TREM2 were identified that were associated with Alzheimer's disease. In this study, we identified 5 (8.3%) LPVs and 18 (30%) VUSs in known dementia-related genes in apolipoprotein E ε4 noncarrying Korean patients with early-onset Alzheimer's disease.