Causes and Risk Factors of Familial Heart Disease

Most of these diseases have an autosomal dominant inheritance pattern. This means you can get the disease by receiving the abnormal gene from only one of your parents. Men and women are at equal risk of inheriting the disease, and an affected person has a 50% chance of having a child with the disease (per pregnancy).  However, even when the abnormal gene is inherited, the penetrance (probability of manifesting heart disease) and expressivity (degree of severity of the heart disease) can vary greatly, even within the same family. 

There are also diseases with an autosomal recessive inheritance pattern, although these are much less frequent. In this case, men and women are at equal risk of inheritance, but for the disease to manifest itself the affected person must have received an altered gene from both parents. In this case, the risk of inheriting the disease will vary depending on whether the parents are affected, are only carriers of an altered gene, or are healthy individuals. 

Finally, there are rare cases of sex-linked inheritance, where the abnormal gene affects the X chromosome. In these cases, incidence of the disease is higher in men, with women usually acting as carriers or presenting with less severe heart disease.