Any disease for which drugs are not usually developed because it is too rare to make the development profitable.

(medicine) An infectious viral disease characterised by fever and chest pain.

globoid cell leukodystrophy, or galactosylceramide lipidosis; a rare, often fatal degenerative disorder that affects the myelin sheath of the nervous system

An infectious neurological syndrome caused by infection with Borna disease virus.

A rare genetic disorder caused by deficiency of an enzyme known as lysosomal acid lipase (LAL or LIPA), necessary to break down certain lipids.

A very rare skeletal condition of uncertain etiology, characterized by the uncontrolled proliferation of distended, thin-walled vascular or lymphatic channels within bone, which leads to resorption and replacement of bone with angiomas and/or fibrosis.

Alternative form of Bekhterev's disease

(dated, medicine) Ankylosing spondylitis.

(economics) An increase in the value derived from the natural-resources sector of the economy, leading to a rise in the valuation of the currency increasingly based on the natural-resources sector, and thus causing a deterioration in the manufacturing sector by making the manufactured goods less competitive in the export marketplace compared to those manufactured by economies with lower valuation currencies, because they are relatively more expensive.

Hurler syndrome