Inheritance of Canavan Disease and Affected Population
Canavan disease is a recessive gene. To get Canavan both of the parents have to be carriers of the recessive gene. Then there will be a 25% chance that you will have Canavan disease. There is also a 50% chance that you won't have Canavan disease but you will be a carrier of Canavan and there is a 25% chance that you won't have it and you won't be a carrier of Canavan.
Canavan disease affects all cultures and races, but the highest chance is in the Ashkenazi Jewish (live in Central and Eastern Europe) faith. The Ashkenazi have a 1 in 6,400 to 13,500 chance of being affected with Canavan. It is unknown how many people worldwide are affected by the disease