choline acetyltransferase (ChAT), the enzyme that synthesizes acetylcholine (Ach), is thought to be present in both cerebrospinal fluid (CSF) and plasma (Karami, Darreh-Shori, Schultzberg, & Eriksdotter, 2021), and acetylcholinesterase (AchE) is an enzyme that metabolizes the Ach at synaptic cleft, resulting in cognitive impairment (Patel, Raghuwanshi, Masood, Acharya, & Jain, 2018). The gene discussed is CHAT; the disease is Cognitive impairment.