Tangier disease or hypoalphalipoproteinemia is an extremely rare inherited disorder characterized by a severe reduction in the amount of high density lipoprotein (HDL), often referred to as "good cholesterol", in the bloodstream.

This inability to transport cholesterol out of cells leads to a deficiency of high-density lipoproteins in the circulation, which is a risk factor for coronary artery disease.

[citation needed] This condition is inherited in an autosomal recessive pattern, meaning that for the phenotype to appear, two copies of the gene must be present in the genotype.

[citation needed] People affected by this condition also have slightly elevated amounts of fat in the blood (mild hypertriglyceridemia) and disturbances in nerve function (neuropathy).

[5] In 1959, a five-year-old patient named Teddy Laird from Tangier Island, Virginia, presented with strikingly large and yellow-orange tonsils which were removed by armed forces physicians.

After finding the same symptom in Teddy's sister, an investigation revealed an extremely high number of foam cells (cholesterol ester-laden macrophages) in not only the tonsils, but also in a wide range of tissues, including the bone marrow and spleen.

During a second trip to the island, they found that the family had very low levels of HDL cholesterol, suggesting a genetic basis of the disease.