Tangier disease

Tangier disease, also called hypoalphalipoproteinemia, is an extremely rare inherited disorder in which the blood contains a severely reduced amount of high density lipoprotein, often called good cholesterol. About one hundred cases have been identified worldwide. Mutations at chromosome 9q31 produce a defective ABCA1 transporter that cannot move cholesterol and phospholipids out of cells, so cholesterol esters collect in tissues such as the tonsils, which look enlarged and yellow or orange, and also the lymph nodes, bone marrow, liver and spleen. Neuropathy and early cardiovascular disease are the most serious consequences. It is inherited in an autosomal recessive pattern. The disorder takes its name from Tangier Island off the coast of Virginia, where it was first recognised in 1959 in a young boy with striking tonsils, and later work by Donald Fredrickson linked it to very low HDL levels. Drugs that raise HDL do not help, and the main treatment is a low-fat diet.