Inheriting Gaucher

A person with just one defective gene and one normal gene for glucocerebrosidase is a ‘carrier’ of Gaucher disease. (Glucocerebrosidase is the enzyme that is missing or deficient in Gaucher disease.) Carriers do not develop the disease because one of the two genes is normal, so enough normal enzyme is produced to prevent the fatty substance glucocerebroside from accumulating in cells. Although Gaucher carriers will not have symptoms of the disease themselves, the odds are 50:50 that the “Gaucher gene” will be passed on to each of their children.

What are the odds of having children who have Gaucher disease or are carriers?

When one parent is a carrier and one is an unaffected parent, the child has a 50% chance of becoming a carrier. When both parents are carriers, there is a 50% chance their child will become a carrier and a 25% chance that the child will inherit the disease. There is also a 25% chance that the child will neither be affected nor a carrier. That means with each pregnancy, carrier parents have a 3 in 4 (75%) chance of having a non-Gaucher child and a 1 in 4 (25%) chance of having a child affected by Gaucher disease.

(Fig. 1) Gaucher disease is not a gender linked disorder. Both males and females can be carriers and affected with Gaucher disease.

The Ashkenazi connection

Among individuals of Eastern European (or Ashkenazi) Jewish descent, the incidence of Type 1 Gaucher disease is considerably higher (as many as 1 in 450 people) than in the general population
(1 in 40,000-60,000). Approximately 1 in every 12 to 15 individuals of Ashkenazi Jewish descent is a carrier.