Roussy-Lévy is inherited through autosomal dominant genetic transmission. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. In dominant disorders, a single copy of the disease gene (received from either the mother or father) will be expressed “dominating” the other normal gene and resulting in the appearance of the disease. The risk of transmitting the disorder from affected parent to offspring is 50 percent for each pregnancy regardless of the sex of the resulting child.
Scientific evidence published in 1998 indicated that Rousy Lévy Syndrome appears to be a form of Charcot Marie Tooth Disease because it is caused by a partial duplication of the same gene that causes CMT (17p11.2).