Pirovano A, Lorenzi C, Serretti A, Ploia C, Landoni S, Catalano M, Smeraldi E and Lorenzi C. Genetics in Medicine. 2005;7: 455–457.
To confirm the role of clock SNPs in mood disorders, an Italian study was performed, and a rare clock gene SNP was found to only be present in those with mood disorders. None of the 76 healthy controls and 2 of the 1037 ill patients had this rare mutation.
These patients both had disturbed sleep schedules and difficulty maintaining consistent daily rhythms. However, a statistical analysis was not performed to estimate the size of the mutation’s effect or to determine whether the results were simply due to variability.