Harlequin Ichthyosis is a severe genetic skin disease, which affects the foetus in the womb, causing the skin to be around 10 times thicker than normal and grow at an exceptionally fast rate. When born, the child’s whole body is encased in an ‘armour’ of thick white plates of skin, separated by deep red fissures.
As the skin barrier is severely compromised, babies are extremely susceptible to infection, are at risk of dehydration due to increased water loss across the skin, and also have impaired temperature control. The thickness of the skin plates around the chest can also cause restricted breathing. The disease can lead to permanent damage to fingers and toes, while also causing the eyelids to turn ‘inside-out’.
The mortality rate of the disease is extremely high, particularly during the neonatal period. Prognosis for babies that survive the first year of life is improving, though constant care is required to avoid infection and ensure that the skin is kept constantly moisturised.
Harlequin Ichthyosis is caused by recessive mutations in the gene ABCA12. ABCA12 is known to be localised within the upper layer of the epidermis (outer part of skin), however, its precise role is as yet unknown, but thought to be associated with lipid transport and keratinocyte (skin cell) differentiation.
There has been little research into Harlequin Ichthyosis due to its rarity, but SHHIRT are hoping to change this by raising funds for important research and facilities for both the routine diagnostic testing the ABCA12 gene, for which there is no service within the UK that offers this, improvement in the prenatal diagnosis and to develop gene targeted therapies.