X-linked ichthyosis X-linked ichthyosis X-linked ichthyosis (XLI) (also known as ") is a skin condition caused by the hereditary deficiency of the steroid sulfatase (STS) enzyme that affects 1 in 2000 to 1 in 6000 males. XLI manifests with dry, scaly skin and is due to deletions or mutations in the "STS" gene. XLI can also occur in the context of larger deletions causing contiguous gene syndromes. Treatment is largely aimed at alleviating the skin symptoms. The term is from the Ancient Greek 'ichthys' meaning 'fish'. The major symptoms of XLI include scaling of the skin, particularly on the neck, trunk, and
Ichthyosis hystrix gene. It is named after Helen Ollendorff Curth (1899-1982), a German-Jewish dermatologist, and Madge Thurlow Macklin (1893–1962), an American medical geneticist, and is one of the first syndromes named after two women. Also known as ichthyosis hystrix gravior or porcupine man. This disease is characterised by spiny scales which cover the entire body except the face, genitals, palms and soles. The only known cases were in Edward Lambert (known as the porcupine man) who was exhibited in front of the Royal Society in London in 1731 and three generations of his descendants. No cases of this disease are now known