ATP7A Disorders (Menkes Disease and Occipital Horn Syndrome)
What are ATP7A disorders?
ATP7A disorders, which include Menkes disease and occipital horn syndrome, are caused by the body not making a specific protein that is important for regulating copper levels in the body. Our bodies need small amounts of copper for healthy development. In Menkes disease, not enough copper reaches the brain and liver, and too much copper builds up in the kidneys and small intestines. The signs and symptoms of Menkes disease usually appear at age 2-3 months and include slow growth, seizures, developmental disabilities and characteristic sparse, twisted hair. The signs of occipital horn syndrome are less severe, and typically include bone calcifications, loose joints and mild intellectual challenges.
How common are ATP7A disorders?
ATP7A disorders affect mostly males, and are found in about 1 in 100,000 babies born in the United States each year.
What can be done for ATP7A disorders?
Identifying these conditions early is essential, and can lead to reduced symptoms and an improved quality of life. Certain symptoms of these conditions can be treated (or prevented) in some babies by giving a special form of copper injections (shots) as soon as they are diagnosed.
How are ATP7A disorders inherited?
ATP7A disorders are caused by changes in the ATP7A gene. The ATP7A gene is located on the X chromosome, so ATP7A disorders are called X-linked inherited conditions. Males have one copy of the X chromosome while females have two. For males, a change in the ATP7A gene on their only X chromosome can cause an ATP7A disorder. For females, an alteration in the ATP7A gene on one X chromosome but a functioning copy on the other X chromosome usually does not result in signs or symptoms of an ATP7A disorder. Instead, this female is considered to be a carrier, because she can pass on the X-chromosome with the altered ATP7A gene to her children. If a baby girl is identified as a carrier for an ATP7A disorder through Eli screening, genetic counseling and additional testing in the parents is recommended.