X-linked ichthyosis is a rare genetic skin disorder seen in men. Patients with this condition develop rough scales, especially on their extremities, and may experience dry skin and irritation because of the scaling. Treatment focuses on softening and removing the scales and moisturizing the skin to keep the patient comfortable. Women act as carriers and usually do not experience any health problems, although sometimes they have difficulty in labor and delivery.
This genetic condition is referred to as “x-linked” because the genes involved are located on the X chromosome. In men, who only inherit one copy of this chromosome, any defective genes will be amplified, because there are no corresponding genes to cancel them out. The defective gene causes a deficiency in an enzyme, steroid sulfatas, which plays a role in breaking down and shedding old skin. Women with two copies of the gene usually produce enough of the enzyme that they shouldn't experience skin symptoms.
Signs of X-linked ichthyosis start to appear shortly after birth. Infants will develop crusty gray to brown scales and in some cases exhibit corneal opacity. As they grow, these scales can harden and cause increasing discomfort. Treatment options can include medications to soften and break up the scales, as well as topical creams for the skin. Some patients may experience fertility problems related to testicular involvement, and men with X-linked ichthyosis may want to consider a medical evaluation if they want to have children, so they can learn more about their fertility.
This skin condition should not cause any other medical problems, although it is possible for a patient to have unrelated congenital issues. Patients need to be careful about managing their skin but can usually engage in a wide range of activities, including physical exertion. Some may discover that certain fabrics are more comfortable than others, and may need to accommodate their X-linked ichthyosis by being selective about clothing purchases to keep skin irritation low.
A woman who knows she is a carrier of X-linked ichthyosis has a chance of passing it to her sons. She may have a son without the gene by passing on her healthy version, or her son could inherit the defective X chromosome. A man with the condition will have carrier daughters by passing on his X chromosome. Women who are carriers should make sure this is noted in their medical charts, as it can be relevant to their medical care.