Thelansis

  X-linked ichthyosis (XLI) is a skin disorder caused by a genetic deficiency in the STS gene located on the X chromosome. This leads to abnormal shedding of the skin, resulting in dry and scaly skin with polygonal scales. The condition is typically diagnosed in the first year of life, with some cases manifesting at birth. However, the flexures, palms, and soles remain unaffected, as do the hair and nails. Most XLI patients have partial or complete deletions of the STS gene, resulting in extensive scaling. However, point mutations can also cause a complete deficiency in STS. Female carriers of STS do not show symptoms because of the gene's location on the X chromosome. De novo STS mutations can also occur. XLI is mainly differentiated from ichthyosis vulgaris and other types of ichthyosis, such as lamellar ichthyosis. Ichthyosis vulgaris is inherited in an autosomal dominant pattern, with symmetrical light grey scaling typically appearing after three months of age. Flexion zones ...

 X-linked ichthyosis (XLI) is a skin disorder caused by a genetic deficiency in the STS gene located on the X chromosome. This leads to abnormal shedding of the skin, resulting in dry and scaly skin with polygonal scales. The condition is typically diagnosed in the first year of life, with some cases manifesting at birth. However, the flexures, palms, and soles remain unaffected, as do the hair and nails. Most XLI patients have partial or complete deletions of the STS gene, resulting in extensive scaling. However, point mutations can also cause complete deficiency in STS. Female carriers of STS do not show symptoms because of the gene's location on the X chromosome. De novo STS mutations can also occur. XLI is mainly differentiated from ichthyosis vulgaris and other types of ichthyosis, such as lamellar ichthyosis. Ichthyosis vulgaris is inherited in an autosomal dominant pattern, with symmetrical light grey scaling typically appearing after three months of age. Flexion zones are a...