Apolipoprotein E (Apo E) genotyping is sometimes requested when a patient has significantly elevated cholesterol and triglyceride concentrations, when a patient presents with xanthomas on their skin and the doctor suspects Type III hyperlipoproteinaemia (also known as dysbetalipoproteinaemia, remnant disease or broad beta disease); or very rarely when family members have apo E e2/e2 and a doctor wants to see if the patient may be at a higher risk for early heart disease.