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
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
Asymmetrical bone growth of the face.
Bone pain and discomfort.
Loss of mobility.
Rickets or osteomalacia.
Uneven bone growth of the legs (causing a limp).
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.