Rs104894561

rs104894561, also known as Thr4Ala or T44A, is a SNP in the casein kinase 1, delta CSNK1D gene.

Heterozygotes for rs104894561 have been reported to have a sleep disorder, Familial Advanced Sleep Phase syndrome 2 (FASPS2), and it is therefore considered to be inherited as an autosomal dominant trait. The condition is marked by a ~4 hour shift towards earlier bedtime and rising time compared to most people.