Danon Disease is a rare genetic condition caused by a mutation or deletion on the X chromosome. It is a storage disorder that causes the build-up of toxic materials in the body. These toxins can cause issues with the heart, muscles, and brain. Because Danon is associated with the X chromosome, the disease may look different in XX (considered female) people than in XY (considered male) people.

The classic type of Fabry Disease begins in early childhood, and symptoms can be severe. The first symptom in children as young as 2 is often pain in the hands and feet. A later-onset type of FD occurs in those who produce some α-Gal A, and this type is often limited to heart issues. Later-onset FD may be mistaken for HCM. LVH in males with classic Fabry shows up on average around age 30. In females with classic Fabry, LVH is more likely to appear around age 50. For those with later-onset Fabry, the average age to develop LVH is around 55, for both males and females.

Amyloidosis is a disease caused by abnormal proteins in the body. When there are too many abnormal proteins, they gather in different organs and cause them to stop working properly.

Friedreich's Ataxia (FA) is a rare genetic condition. It presents in younger people than other forms of ataxia (a loss of muscle coordination that can affect balance, speech, and other motor functions). Because FA can cause the heart muscle to become thick, it can look like hypertrophic cardiomyopathy. For this reason, it's considered one of the HCM spectrum disorders.

PRKAG2 syndrome, a rare hypertrophic cardiomyopathy.