What are the symptoms? In FH, there is a high level of blood LDL cholesterol and a greatly increased risk of coronary heart disease (CHD) at an early age. Xanthomas (fatty deposits) on the tendons of the back of the hand or Achilles tendon, corneal arcus (white ring around the iris) in younger people, and xanthelasmata (yellow deposits round the eye or eyelids) may be present. Most children and young adults with FH have no symptoms, although fatty deposits start to appear in the arteries in childhood. Half of men and one quarter of women with FH who are not diagnosed develop heart disease including angina and heart attacks before age 50. Very rarely children may have ‘double dose’ FH (homozygous FH). These children develop xanthomas in early childhood and heart disease in their teens. What are the causes? FH is a genetic condition caused by mutations in the low-density lipoprotein receptor (LDLR), apoliprotien B (APOB) and protein convertase subtilisin/klexin (PCSK9) genes. How is it diagnosed? It is important to identify FH in childhood, particularly in families in which CHD occurs early in adult life. Diagnosis is achieved by taking a blood sample for a lipoprotein profile, or by genetic testing if the FH gene mutation if the family is known. How is it treated? Effective treatment in lowering blood cholesterol is available using a combination of diet, drugs and lifestyle changes. A diet low in total and saturated fat can be followed by children over two years of age. Spreads and yoghurt drinks containing plant sterols and stanols can help to lower cholesterol. Parents may wish to seek guidance from a dietician experienced in lipid management and a specialist children’s lipid clinic. Drug treatment is often used in children over 10 years at risk of CHD to lower cholesterol. The main class of drugs used are statins. These come in tablet form and work by slowing down the production of cholesterol in the liver. Statins are thoroughly tested, with few side effects in childhood and are very effective at lowering LDL cholesterol. Sometimes the type of statin used has to be changed because of side effects or to obtain a better effect. Children with homozygous FH are treated during early childhood with high dose statin medication and plasma apheresis, where LDL cholesterol is removed from the blood at fortnightly intervals. Inheritance patterns and prenatal diagnosis Inheritance patternsFH is inherited in an autosomal dominant pattern, so an affected child will have one affected parent; the homozygous form is recessive and both parents will have FH. . Prenatal diagnosisIf the gene mutation in the family is known, prenatal diagnosis of FH is possible but rarely required. It is not possible to find mutations in up to one third of individuals. Is there support? HEART UK Helpline: 0345 450 5988Email: firstname.lastname@example.orgWebsite: heartuk.org.uk The Group is a Registered Charity in England and Wales No. 1003904. It offers information and support to anyone affected by raised cholesterol, including healthcare professionals. Group details last updated December 2014.