McCune Albright Syndrome

McCune-Albright syndrome is a genetic condition that affects your bones, skin and endocrine system, causing café-au-lait skin pigmentation, scar tissue forming on bones (fibrous dysplasia) and irregular function of growth-regulating glands that produce hormones. Treatment alleviates symptoms of the condition and leads to a normal life expectancy, but there isn’t a cure.

Other names of McCune Albright Syndrome #

• Fibrous dysplasia

• Albright

Causes of McCune Albright Syndrome #

• A mutation of the GNAS1 gene causes McCune-Albright syndrome.

• The GNAS1 gene makes proteins that regulate hormone activity.

• The mutation causes an enzyme (adenylate cyclase), which is a type of protein, to overproduce hormones and cause symptoms of McCune-Albright syndrome.

• The genetic mutation is the result of a change in DNA that happens after conception (somatic mutation) and isn’t a condition that’s passed from parents to the child.

• The genetic mutation is not the result of something that the parents did or did not do during pregnancy.

• There have been no proven cases of people with McCune-Albright syndrome having a child with the same condition.

• The cause of somatic mutations is unknown and research suggests they occur randomly or sporadically.

Symptoms of McCune Albright Syndrome #

Bone symptoms #

• Asymmetrical bone growth of the face.

• Bone pain and discomfort.

• Loss of mobility.

• Rickets or osteomalacia.

• Scoliosis.

• Short stature.

• Uneven bone growth of the legs (causing a limp).

Skin symptoms #

• Babies born with McCune-Albright syndrome may have patches of skin that are a different color than the rest of the skin on their body (skin pigmentation).

• These patches normally take on a light brown to dark brown color and appear with uneven, jagged borders.

• These spots may only show up on one side of their body.

• Café-au-lait spots may become more prevalent on their skin as your child becomes older.

Endocrine system symptoms #

• The pituitary gland produces too many growth hormones, resulting in large hands and feet, rounded facial features and/or arthritis called acromegaly.

• The adrenal glands produce too much cortisol (stress hormone), which causes obesity and delayed growth called Cushing’s syndrome.

Diagnosis of McCune Albright Syndrome #

Tests that diagnose McCune-Albright syndrome include:

• Blood tests to check endocrine function.

• Genetic testing to identify the gene mutation responsible for symptoms, which usually involves taking a biopsy of their skin or other tissues.

• Imaging tests like an X-ray to examine bone growth.

Treatment of McCune Albright Syndrome #

• Medicine to treat bone growth symptoms like bisphosphonates, which reduce the risk of bone fractures.

• Medicine to treat early puberty like aromatase inhibitors.

• Medicine to treat hyperthyroidism like antithyroids.

• Physical therapy and occupational therapy to target mobility challenges.

• Surgery to treat bone growth symptoms like fibrous dysplasia.