ABHD12 encodes a serine hydrolase with dual enzymatic functions critical for lipid signaling in the nervous system. The enzyme primarily functions as a lysophosphatidylserine (lyso-PS) lipase, mediating hydrolysis of lyso-PS, a signaling lipid that regulates immunological and neurological processes 1. ABHD12 also exhibits monoacylglycerol lipase activity, hydrolyzing 2-arachidonoylglycerol (2-AG) and thereby regulating endocannabinoid signaling pathways 1. The enzyme accounts for approximately 9% of total brain 2-AG hydrolysis and is highly expressed in microglia 1. Mechanistically, ABHD12 localizes to different cerebellar regions and cells compared to ABHD16A, with cerebellar lyso-PS levels being most affected by ABHD12 deletion 2. Loss-of-function mutations in ABHD12 cause PHARC syndrome (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and cataract), a rare neurodegenerative disorder characterized by lyso-PS accumulation in the brain 32. Clinical manifestations include demyelinating polyneuropathy (91% of patients), hearing loss (86%), retinitis pigmentosa (82%), cataracts (86%), and cerebellar ataxia (74%) 3. The variable clinical phenotype and age of onset make diagnosis challenging, emphasizing the need for multidisciplinary evaluation and genetic testing 3.