Harlequin Baby Syndrome

Ichthyosis is a group of genetic skin disorders caused by gene mutations. The disorder is usually present at birth and continues throughout a person's life. Harlequin baby syndrome, or harlequin ichthyosis, is a rare and usually lethal form of ichthyosis. There are no statistics on what percent of babies are born with harlequin ichthyosis.

Cause

• The ABCA12 gene, on chromosome 2, directs the production of proteins necessary for normal skin growth. Mutation of this gene is the cause of harlequin ichthyosis. The gene is an autosomal recessive. For the baby to be affected and show symptoms, he must get one gene from each parent. Most parents are carriers with no symptoms, which mean they have only one of the genes. Since both parents of an affected baby has the gene, full siblings have a one-fourth chance of having it, a one-fourth chance of not being a carrier, and a one-half chance of being a carrier. Unaffected siblings have a two-thirds chance of being carriers. All children of a person with harlequin ichthyosis will be carriers. If their partner is a carrier, half their children may have a gene from each parent and be affected, while the other half may carry one copy of the gene.

Symptoms

• This mutation makes the skin hard with thick scales. The term "harlequin" means to have a diamond shape. The hard, thick skin makes triangle and diamond-shaped plates. Eyes, nose, mouth and ears are affected, often pulling the baby's mouth wide open. This hard skin does not keep moisture in, causing dehydration, and disrupts the body's ability to regulate temperature. It can also make chest movement and breathing difficult. Babies usually have microcephaly (small head) and a deformed face. In survivors, some have short stature and may have neurological, kidney and lung abnormalities.

Prognosis

• Most babies born with harlequin baby syndrome used to die quickly, within two days, due to infections and other problems. With specialized medical treatment to control temperature, prevent fluid loss and infections, treat skin conditions and provide physical therapy, more babies are surviving into childhood and longer. Survivors shed the hard skin and develop scaling and other skin symptoms over most of their bodies, which require lifelong treatment. There are teens in both the U.S. and Great Britain who have lived past the projected 14 years and are doing well.

Testing

• If you have harlequin ichthyosis in your family or suspect your baby may have it, get genetic testing done before pregnancy, if possible, for you and your partner. If you are already pregnant, testing can be done at 23 weeks' gestation and decisions made at that time. Discuss concerns with your doctor and make sure your baby is born in a hospital that is capable and has been alerted to possible problems.

Support and Information

• The only nationally registered support and information group in the U.S. for harlequin baby syndrome is FIRST.

  Foundation for Ichthyosis and Related Skin Types
  1364 Welsh Road G2
  North Wales, PA 19454
  Phone [phone]