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
Heterogeneous condition also define a "medical condition" as any illness, injury, or disease except for psychiatric illnesses. As it is more value-neutral than terms like "disease", the term "medical condition" is sometimes preferred by people with health issues that they do not consider deleterious. It is also preferred when etiology is not unique, because the word disease is normally associated to the cause of the clinical problems. On the other hand, by emphasizing the medical nature of the condition, this term is sometimes rejected, such as by proponents of the autism rights movement. The term is also used in specialized areas of