High cholesterol is often regarded as a result of unhealthy lifestyle or diet choices, however, it can also be passed down through families in the genes. Familial hypercholesterolaemia (FH in short) is a genetic disorder caused by mutations in certain gene that makes the body unable to effectively remove low-density lipoprotein cholesterol (LDL-C), otherwise known as bad cholesterol. As a consequence, LDL-C tends to build up in the vessels and could lead to early cardiovascular events.

Familial Hypercholesterolaemia: A Common Genetic Disorder

FH is a common inherited disorder with an estimated prevalence of 1:200. Chinese and non-Chinese share a similar statistic. Since FH is largely asymptomatic, it is often undiagnosed and untreated. In 2013, only 500 people in Hong Kong are diagnosed with FH.

According to the European Society of Cardiology, patients with FH bear a higher risk of developing cardiovascular diseases. Male FH patients at age 50, for example, are 50% more likely to have cardiovascular diseases than men who are of the same age; female FH patients at age 60, similarly, are 30% more likely to be diagnosed with cardiovascular diseases than their counterparts.

Almost all FH patients have at least one affected parent. If one of the parents has FH, there is a 50% chance of each child having the same disease. The risk even reaches as high as 75% if both of the parents are with FH.   

High Cholesterol Caused by Unhealthy Lifestyle VS Familial Hypercholesterolaemia

Compared with high cholesterol caused by unhealthy lifestyle, FH is usually associated with a higher level of cholesterol in blood. In some cases, FH patients may have elevated LDL-C and total cholesterol levels at >4.9 mmol/L and >7.5 mmol/L respectively, or even skyrocketed to double digits. Also, patients with severe FH may observe yellow deposits on the skin around the eyes and the hands, elbows, buttocks, knees and ankles.

In terms of treatment, since patients with FH always have excessively high LDL-C levels, their responses to medications might not be as good and it is more difficult for them to reduce their LDL-C to desired levels. At the same, they often require higher doses of medication which could probably increase the risk of side effects. A new therapy, called PCSK9 inhibitors, is now recognized to be an alternative in managing FH. Some studies have discovered that high-potency PCSK9 inhibitors are effective in lowering LDL-C levels in a short period of time.

Advice for Patients with Familial Hypercholesterolaemia

If your parents or grandparents have undergone cardiovascular surgery in younger times or even passed away due to cardiovascular diseases, you and your family members should take extra caution regarding your/their own cholesterol level and cardiovascular health. Early diagnosis and intervention have been proven to be highly effective in reducing the risk of future cardiovascular events. It is also important for couples with FH to seek opinion from their family doctor or Cardiology specialist if they are considering having children.

 

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