CSF-MCH levels differed between AD with MMSE≤20 (n = 15), AD with MMSE≥21 (n = 18) and HS, (F(2,62) = 6.997, p<0.01) with post-hoc analyses showing higher levels in AD with MMSE≤20 compared to HS (p<0.001). The gene discussed is PMCH; the disease is Alzheimer disease.