The carrier frequency and incidence of alpha thalassemia vary by the type and population. Carrier frequency of this condition is reported to be the highest in individuals of Southeast Asian, African, West Indian, and Mediterranean descent.
Clitheroe Castle Museum is adjacent to the castle. The castle was listed as a Scheduled Monument on 10 April 1915 (and later, under the Ancient Monuments and Archaeological Areas Act 1979 law).It was Grade I listed on 19 May 1950.t has been suggested that Clitheroe Castle may have been first built before 1086 as there is reference to the  castellatu Rogerii pictaviensis  in the Domesday Book entry for nearby Barnoldswick. However, it is likely the passage refers to another castle.
Stone Keep Castle. This type of castle soon replaced the Motte and Bailey castles as it offered a better form of defence. A stone keep was the central feature, with thick walls and few windows. Entrance to the keep was by stone steps leading to the first floor.otte and Bailiey castles were the earliest form of castles built completely from scratch by the Normans. As their name suggests they had two parts the Motte and the Bailey. The Motte was a large hill made of earth on which was built a wooden keep or lookout.