Genetic Considerations

While most cases of acromegaly are not inherited, mutations in the GNAS1 gene can cause GH-secreting pituitary adenomas (somatotrophinomas). These can be transmitted in an autosomal dominant pattern. Familial acromegaly may also be a feature of multiple endocrine neoplasia type I (MEN I), an autosomal dominant disorder that includes peptic ulcer disease and pituitary, parathyroid, and pancreas endocrine abnormalities.


Diagnosis of acromegaly usually occurs after the age of 40 in men and 45 in women, and occurs more frequently in women than in men. Ethnicity and race have no known effects on the risk for acromegaly.

32 Acromegaly


HISTORY. The course of acromegaly is slow, with very gradual changes over 7 to 10 years. Reviewing a patient's old photographs may reveal the progressive changes in facial features. Determine if the patient has had a change in hat, glove, ring, or shoe size because of an overgrowth of the hands and feet. Ask the patient if he or she has had headaches or visual disturbances, which in acromegaly are caused by the growth of the adenoma, which exerts pressure on brain tissue and cranial nerves III, IV, and VI. Establish a history of altered sexual function, which may be an indicator of decreased gonadotropin production. Ask about the presence of pain in the hands, feet, and spine, which is probably caused by bone growths; also ask about problems with chewing, swallowing, or talking, which may be caused by tongue, jaw, and teeth enlargement. Note the presence of a deepening of the voice, recurrent bronchitis, excessive sweating, heat intolerance, fatigue, and muscle weakness. Check for a family history of pituitary tumors.

PHYSICAL EXAMINATION. The initial physical changes that occur with acromegaly result from an enlargement of the bones in the head, hands, and feet. The parts of the head that may be enlarged by acromegaly include the jaw, forehead, nose, tongue, and teeth. Observe the patient's facial appearance, noting an enlarged supraorbital ridge, thickened ears and nose, or jutting of the jaw (prognathism). If the patient has an enlarged tongue, note any respiratory alterations.

Examine the patient's fingers for signs of thickening. Inspect the patient's torso, noting a barrel chest or kyphosis. Note any signs of bowed legs. Assess the patient's skin for signs of oiliness or excessive sweating (diaphoresis). Assess the patient's hand strength. Test the patient's vision for bitemporal hemianopia and loss of visual acuity. Note a deep, hollow-sounding voice.

PSYCHOSOCIAL. Patients with acromegaly undergo some dramatic physical changes that can lead to permanent dysfunctions. These changes affect the patient's self-concept and ability to perform expected roles. Note any irritability, hostility, or depression.

Diagnostic Highlights

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