Aplasia Cutis Congenita

 Aplasia Cutis Congenita

DISEASE OVERVIEW

Aplasia Cutis Congenita is a rare disorder with a complicated pattern of inheritance. Babies are born with the absence of certain layer(s) of skin, most often on the scalp, but also on the trunk, and/or arms and legs. The affected area is typically covered with a thin, transparent membrane. The skull and/or underlying areas may be visible and be abnormally developed. Aplasia Cutis Congenita may be the primary disorder or it may occur in association with other underlying disorders.

SIGNS & SYMPTOMS

Individuals born with Aplasia Cutis Congenita lack skin (and therefore hair), in localized areas of the body, usually, but not always, on the scalp (70 percent of cases). In some cases, the trunk, arms, and/or legs may also be involved. Sometimes, the underlying bone may be missing as well as the skin. The affected area(s) are usually replaced with a thin transparent membrane. In some cases, these affected structures and other organs may be seen through the transparent membrane.

Most individuals with Aplasia Cutis Congenita exhibit no other abnormalities. However, in some rare cases, they may experience other physical characteristics including abnormalities of the ears, a form of paralysis (palsy) affecting one side of the face, an abnormally large head (macrocephaly), and/or congenital heart anomalies.

Aplasia Cutis Congenita may also occur as a physical condition characteristic of several other disorders, including Adams-Oliver Syndrome, Aplasia Cutis Congenita-Gastrointestinal, and Johanson-Blizzard Syndrome. (For more information on these disorders, see the Related Disorders section of this report.)

CAUSES

Aplasia Cutis Congenita is a rare disorder that may be inherited as an autosomal dominant or autosomal recessive trait. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother.

In dominant disorders, a single copy of the disease gene (received from either the mother or father) will be expressed “dominating” the other normal gene and resulting in the appearance of the disease. The risk of transmitting the disorder from affected parent to offspring is 50 percent for each pregnancy regardless of the sex of the resulting child.

In recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is 25 percent. Fifty percent of their children risk being carriers of the disease, but generally will not show symptoms of the disorder. Twenty-five percent of their children may receive both normal genes, one from each parent, and will be genetically normal (for that particular trait). The risk is the same for each pregnancy.

DISORDERS WITH SIMILAR SYMPTOMS

Aplasia Cutis Congenita may be one of the symptoms of the following disorders.

Adams-Oliver Syndrome is a rare inherited disorder characterized by the absence of bone in areas of the skull and bald ulcerated areas of overlying scalp. These skull and scalp abnormalities usually heal spontaneously during the first few months of life, but in a few cases plastic surgery may be necessary. Limb abnormalities may vary in severity. Fingers and toes may be absent or shorter than normal, and the longer bones in the hand may be absent. In some severe cases, the leg below the midcalf may be absent. (For more information on this disorder choose “Adams-Oliver Syndrome” as your search term in the Rare Disease Database.)

Aplasia Cutis Congenita-Gastrointestinal is a rare disorder inherited as an autosomal recessive trait. This disorder is characterized by extensive Aplasia Cutis Congenita and the absence of a normal opening in the canal that goes from below the mouth to the stomach (esophagus), the tube-shaped part of the stomach, and/or the short part of the small intestine that joins the stomach (duodenum). Other symptoms found in some patients with Aplasia Cutis Congenita-Gastrointestinal may be skin separation and/or low-set ears. This disorder is rapidly progressive.

Johanson-Blizzard Syndrome is a form of ectodermal dysplasia that is characterized by nose, scalp and hair defects, as well as a lack of teeth, deafness, short stature, a lack of motor development and malabsorption problems. The most striking feature of this syndrome is the beaklike appearance of the nose. Three-fourths of the patients have a protrusion over the rear fontanelle of the skull at birth which gets thick and hard as the child grows. Their teeth are peg-shaped and they have thin hair that sweeps up from the forehead. Patients with Johanson-Blizzard Syndrome show marked hearing loss from birth as well as motor and mental retardation. Bone growth is delayed and there may be associated intestinal, absorption and genital defects. (For more information on this disorder choose “Ectodermal Dysplasia”as your search term in the Rare Disease Database.)

STANDARD THERAPIES

Diagnosis of Aplasia Cutis Congenita is generally obvious at birth through the characteristic absence of skin affecting the scalp, trunk, arms, and/or legs.

Children diagnosed with Aplasia Cutis Congenita should receive a complete medical evaluation to determine whether this disorder is occurring on its own or as a secondary characteristic of another disorder. If Aplasia Cutis Congenita is occurring on its own, affected children should be monitored for symptoms and physical characteristics associated with this disorder.

Medical treatments of Aplasia Cutis Congenita include measures to prevent the drying out of the membrane by soothing, bland ointments. Antibiotics should be used only if signs of bacterial infection are present. The damaged area usually heals spontaneously.

Surgical care may include the repair of multiple scalp defects that usually, but not always, respond to procedures less traumatic than skin grafts. These may include such techniques as tissue expanders to fill in large areas or flap rotation to ease a piece of skin over an affected area.

Genetic counseling may be of benefit for affected individuals and their families.

TYPE OF DOCTOR AND DEPARTMENT: Dermatology SPECIALIST CAN DIAGNOSE THIS DISEASE.