There are hundreds of diseases that are related to changes in our genetic code, but most of them are extremely rare. Mutations or alterations in specific genes may prevent the genes from creating vital proteins or cause alterations in the proteins that they produced. These changes can affect the way that the body functions and cause specific diseases. Some of the disease-related gene mutations are recessive before they cause dysfunction, while others are dominant (a single altered gene copy can cause disease). Some are X- or sex-linked, associated with the X or Y chromosome that determines our gender, and are found only in males or females. Some mutations have arisen and been passed down in specific families and some are more prevalent in individuals of certain ethnic descent.

Genetic testing is a personal choice. Testing for some of the more common genetic diseases may be performed on both a woman and her partner prior to a pregnancy. Couples should talk to a genetic counselor about their ethnicity and family background to determine which tests are the most appropriate and to help them make an informed decision.

Individuals of Ashkinazi (East European) Jewish descent, for example, are at increased risk for inheriting Tay-Sachs, Gaucher, Canavan disease, and Familial Dysautonomia. These genetic diseases can occur when both parents have an abnormal gene that can cause the disease in the child. In both Tay-Sachs and Canavan diseases, there is a buildup of a substance in the child’s brain that prevents normal development. There is no known cure for either disease. Children with Tay-Sachs rarely live past five years of age; children with Canavan disease may live to early adolescence. There are three types of Gaucher disease, each causing too much fatty substance to be stored in the bone marrow, spleen and liver. Although one type of Gaucher disease is fatal, the most common type is not. Treatments are available for individuals with Gaucher disease. Famial Dysautonomia is caused by incomplete development of nerve fibers in the autonomic and sensory nervous systems. There are a variety of symptoms (and their severity), the most noticeable of which is the lack of tears during crying.

Related Pages
Features: The Universe of Genetic Testing