What are the signs and symptoms of McCune Albright syndrome? People with McCune Albright syndrome (MAS) may have symptoms related to bones, the endocrine system, and/or skin. The symptoms can range from mild to severe. Bone symptoms may include: Polyostotic fibrous dysplasia: This is when normal bone is replaced by softer, fibrous tissue. Polyostotic means the abnormal areas may occur in many bones; often they are confined to one side of the body. Replacement of bone with fibrous tissue may lead to fractures, uneven growth, and deformity. When it occurs in skull and jaw it can result in uneven growth of the face. This may also occur in the long bones; uneven growth of leg bones may cause limping. Abnormal curvature of the spine (scoliosis) Cancer: Bone lesions may become cancerous, but this happens in less than 1% of people with MAS. Endocrine symptoms may include: Early puberty: Girls with MAS usually reach puberty early. They often have menstrual bleeding by age 2 (as early as 4-6 months in some), many years before characteristics such as breast enlargement and pubic hair growth are evident. This early onset of menstruation is believed to be caused by excess estrogen, a female sex hormone produced by cysts that develop in one of the ovaries. Less commonly, boys with MAS may also experience early puberty. Enlarged thyroid gland: The thyroid gland may become enlarged (a condition called a goiter) or develop masses called nodules. About half of affected individuals produce excessive amounts of thyroid hormone (hyperthyroidism), resulting in a fast heart rate, high blood pressure, weight loss, tremors, sweating, and other symptoms. Increased production of growth hormone: The pituitary gland may produce too much growth hormone. This can result in acromegaly, a condition characterized by large hands and feet, arthritis, and distinctive facial features that are often described as "coarse." Cushings syndrome: Rarely, individuals with MAS produce too much of the hormone cortisol in the adrenal glands. Cushing's syndrome causes weight gain in the face and upper body, slowed growth in children, fragile skin, fatigue, and other health problems. Skin symptoms may include: Cafe-au-lait spots: Individuals with MAS usually have light brown patches of skin called cafe-au-lait spots. Like the bone lesions, these spots often appear on only one side of the body. Most children have these spots from birth and the spots rarely grow. There are usually not any medical problems caused by these skin changes. The Human Phenotype Ontology provides the following list of signs and symptoms for McCune Albright syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Bone pain 90% Cafe-au-lait spot 90% Generalized hyperpigmentation 90% Hypophosphatemia 90% Precocious puberty 90% Recurrent fractures 90% Reduced bone mineral density 90% Skeletal dysplasia 90% Abnormality of coagulation 7.5% Abnormality of dental enamel 7.5% Abnormality of the palate 7.5% Carious teeth 7.5% Dental malocclusion 7.5% Elevated hepatic transaminases 7.5% Goiter 7.5% Hearing abnormality 7.5% Hypercortisolism 7.5% Hyperparathyroidism 7.5% Hyperthyroidism 7.5% Kyphosis 7.5% Long penis 7.5% Macrocephaly 7.5% Macroorchidism 7.5% Mandibular prognathia 7.5% Neoplasm of the breast 7.5% Neoplasm of the thyroid gland 7.5% Optic atrophy 7.5% Polycystic ovaries 7.5% Sarcoma 7.5% Tall stature 7.5% Testicular neoplasm 7.5% Blindness - Craniofacial hyperostosis - Facial asymmetry - Growth hormone excess - Hearing impairment - Intestinal polyposis - Large cafe-au-lait macules with irregular margins - Pathologic fracture - Phenotypic variability - Pituitary adenoma - Polyostotic fibrous dysplasia - Prolactin excess - Somatic mosaicism - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.