Is Menkes Disease hereditary?

TL;DR: Yes, Menkes disease is a hereditary genetic condition caused by mutations in the ATP7A gene. It follows an X-linked recessive inheritance pattern, meaning it primarily affects males and is typically passed from a carrier mother to her son.

Is Menkes disease hereditary and what is the inheritance pattern?

Menkes disease is strictly a hereditary condition, meaning it is caused by genetic changes passed down through families. It is not caused by environmental factors or events during pregnancy. Menkes disease follows an X-linked recessive inheritance pattern. Because the ATP7A gene is located on the X chromosome, females (who have two X chromosomes) are usually asymptomatic carriers if they have one mutated copy. Males (who have only one X chromosome) will develop the full symptoms of Menkes disease if they inherit the mutated gene, as they lack a second, healthy copy of the gene to compensate.

What is the risk of passing on Menkes disease to children?

The risk of inheritance depends on the biological sex of the child and the carrier status of the parents. For a woman who is a known carrier of the ATP7A gene mutation, the risks for each pregnancy are as follows:

• 50% chance of having a son who inherits the mutation and develops Menkes disease.


• 50% chance of having a daughter who inherits the mutation and becomes a carrier.


• 50% chance of having a son who does not inherit the mutation.


• 50% chance of having a daughter who does not inherit the mutation.

In rare instances, an affected male may survive long enough to reach reproductive age, but historically, individuals with classic Menkes disease have not reproduced. Therefore, the condition is almost exclusively passed down through carrier mothers.

Can Menkes disease occur as a new (de novo) mutation?

While Menkes disease is hereditary, it is estimated that approximately 25% to 30% of cases occur due to a de novo (spontaneous) mutation. This means the genetic change occurs for the first time in the affected child and is not present in the mother’s DNA. Even when a child is the first in the family to have Menkes disease, genetic testing is essential to determine if the mother is a carrier or if the mutation occurred spontaneously, which is critical for future family planning.

How is genetic testing and counseling utilized?

Genetic testing for Menkes disease typically involves molecular genetic analysis of the ATP7A gene to identify pathogenic variants. This testing is recommended for any child exhibiting clinical signs of the disease, such as sparse, kinky hair and developmental delay. Genetic counseling is a vital part of the diagnostic process. Counselors help families understand the ATP7A mutation, interpret test results, and discuss reproductive options, such as prenatal diagnosis via amniocentesis or chorionic villus sampling (CVS), and preimplantation genetic testing (PGT) for families looking to have more children.

Next steps

• Consult with a board-certified clinical geneticist to confirm the diagnosis through ATP7A sequencing.


• Speak with a genetic counselor to map your family history and understand the specific risks for siblings and extended family members.


• Connect with the 74 members of the DiseaseMaps.org community who have experience navigating the complexities of Menkes disease.


• Discuss reproductive planning options, including PGT, if you are a carrier or family member of someone with Menkes disease.

Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment; always consult with your physician or a qualified health provider regarding your specific medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Menkes Disease.


• Orphanet: Menkes Disease (ORPHA:570).


• Online Mendelian Inheritance in Man (OMIM): ATP7A gene (Entry #300011).


• The Menkes Foundation: Resources for families and clinical research updates.