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 follicularis with alopecia and photophobia syndrome form, there is another type where females are partially affected and another where females have full IFAP symptoms. The gene or genes causing this disease are not known. Diagnosis is based on appearance and family history. KID syndrome or keratosis follicularis spinulosa decalvans have some similar symptoms and must be eliminated. Ichthyosis follicularis with alopecia and photophobia syndrome IFAP syndrome is an extremely rare genetic syndrome. It is also known as Ichthyosis follicularis, alopecia, and photophobia syndrome or simply ichthyosis follicularis. It is extremely rare: there were only 10 known cases (all male) in 1998. The main symptoms are given