Why do people with two copies have genetic forms of the disease

Why do people with two copies have genetic forms of the disease

Many genetic diseases are caused by the presence of two copies of a defective gene. This is because genes provide instructions for making proteins, and when a gene is defective, it can produce a non-functional protein. In some cases, having one copy of the defective gene is enough to cause problems, but in other cases, both copies of the gene must be defective for the disease to develop.

There are many different types of genetic diseases, and they can range in severity from mild to life-threatening. Some advanced examples of genetic diseases include:

Cystic fibrosis: This disease affects the lungs and digestive system, and is caused by a defective gene that produces thick, sticky mucus.

Sickle cell disease: This disease affects red blood cells and is caused by a defective gene that makes the cells heart-shaped. Sickle cells can block blood vessels, which can lead to pain, organ damage, and stroke.

Tay-Sachs disease: This disease is a fatal neurological disorder caused by a defective gene that produces an enzyme that breaks down fats in the brain.

There are no cures for existing genetic diseases, but there are treatments that can help manage symptoms and improve the quality of life for people with these diseases. In some cases, genetic testing can be used to identify people who are at risk for a genetic disease, which may allow them to take steps to prevent or prepare for the disease.

How genetic diseases are inherited

Genetic diseases are usually inherited from parents. When parents give birth to a child, they pass on half of their genes to it. If both parents have a copy of the defective gene, there is a 25% chance that the child will inherit two copies of the defective gene and have the condition. There is also a 50% chance that the child will inherit one copy of the defective gene and one copy of the normal gene, and a 25% chance that the child will inherit two copies of the normal gene.

Prevention of genetic diseases

There are several things you can do to prevent genetic diseases. They include:

Genetic counseling: Genetic counselors can provide information and support to people who are at risk of a genetic disease. They can also help couples make an informed decision about having children.

Prenatal testing: Prenatal testing can be used to detect genetic diseases during exposure. If a genetic disease is detected, the father may be able to terminate the pregnancy or be prepared for the birth of a child with this disease.

Carrier screening: Carrier screening can be used to identify people who are carriers of the defective gene. Carriers do not get the disease themselves, but they can pass the defective gene to their children. If both partners in a couple are carriers of the same defective gene, they may have an increased risk of having a child with the disease.

Sources of additional information::

National Institutes of Health

Main Reference in Genetics

March of Dimes

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