Washington: The genetic cause of a rare skin condition that causes the hands and feet to turn white and spongy when exposed to water, has now been identified.
A study led by researchers from Queen Mary, University of London, has provided scientists with an insight into how the skin barrier functions and could help with research into a variety of conditions.
Diffuse non-epidermolytic palmoplantar keratoderma (NEPPK) is a rare condition in which individuals have thickened, yellowish skin over their palms and soles, thickened nails and suffer from excessive sweating.
When their hands and feet are exposed to water, the skin quickly turns white and spongy and individuals are prone to fungal infections .
While prevalence in the general population is estimated at one in 40,000 it is much higher in northern Sweden (up to one in 200 people), where a single ancestral genetic mutation is believed to have originated and then subsequently passed down from generation to generation.
A team led by David Kelsell, Professor of Human Molecular Genetics at Queen Mary studied DNA from a number of families of British and Swedish origin in which the skin condition is present.
Using high throughput DNA sequencing methods they were able to pin down the underlying cause of the condition to mutations in the AQP5 gene, which encodes a water channel protein known as aquaporin 5.
All individuals who have inherited an AQP5 mutation were present with this rare skin condition.