Harlequin-type ichthyosis

Also known as 'Harlequin baby' and 'Harlequin congenita', Harlequin-type ichthyosis is a skin disease characterised by a thickening of the keratin layer in fetal human skin. The sufferer's skin contains large, red, diamond shaped scales and the eyes, ears and genitals may be abnormally contracted. The cracked skin limit's the movement greatly, and allows bacteria and other contaminants to easily penetrate, resulting in serious risk of fatal infection. Restricted movement of the chest can lead to breathing difficulties and respiratory failure. Furthermore, it is more difficult for the affected infant to control water loss and regulate body temperatures.


It is caused by mutations in the ABCA12 gene, which provides instructions for making a protein essential for the normal development of skin cells. The protein plays a major role in the transport of lipids in the epidermis layer of the skin. Some mutations in the ABCA12 gene prevent the cell from making any ABCA12 protein. Other mutations lead to the production of an abnormally small version of the protein that cannot transport lipids properly. A loss of functional ABCA12 protein disrupts the normal development of the epidermis, resulting in the hard, thick scales characteristic of harlequin ichthyosis.


Symptoms

• Severe cranial and facial deformities
• Ears and nose may be absent or poorly developed
• Ectropion  - everted or outward eyelids
• Dryness of skin
• Thickening of skin
• Large, red scales
• Deformed limbs
• Polydactyly – more than the usual number of toes or fingers

Treatment

• Isotretinoin
• Symptomatic treatment - aimed at reducing the signs and symptoms for the comfort and well-being of the patient
• Treat dryness
• Treat infections