Ichthyosis vulgaris is converted to filaggrin which plays a vital role in the structure of the skin). Around 10% of the population have some detrimental mutations to the profilaggrin gene that is also linked to atopic dermatitis (another skin disorder that is often present with ichthyosis vulgaris). The exact mutation is only known for some cases of ichthyosis vulgaris. It is generally considered to be an autosomal dominant condition, i.e., a single genetic mutation causes the disease and an affected person has a 50% chance of passing the condition on to their child. There is some research indicating it may be semi-dominant.
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