Related Self Assessment Question ( Difficulty level - Step 2 ) The mother of a 17-year-old defensive lineman for his high school football team reports that his shoulder pads have permanently stained his neck. All the syndromes listed below are associated with overweight conditions in children. For the other clinical findings in this patient, select the syndrome with which it is most likely to be associated. A. Prader-Willi syndrome B. Laurence-Moon-Biedl syndrome C. Cushing syndrome D. Fröhlich syndrome E. Pseudohypoparathyroidism F. Polycystic ovary syndrome G. Type 2 diabetes EXPLANATION: Patients with type 2 diabetes mellitus have insulin resistance in their skeletal muscles, increased hepatic glucose production, and decreased insulin secretion in response to elevated levels of glucose. They also develop hyperlipidemia and many complications of chronic hyperglycemia. Acanthosis nigricans, as described in the question, is a common finding in type 2 diabetes. The Prader-Willi syndrome is a disorder consisting of hypotonia, hypogonadism, hyperphagia after the newborn period, hypomentia, and obesity. A deletion of a portion of chromosome 15 has been found in approximately 70% of patients. Children affected by this syndrome exhibit little movement in utero and are hypotonic during the neonatal period. Feeding difficulties and failure to thrive can be the presenting complaints in the first year; later, obesity becomes the most common presenting complaint. The enormous food intake of affected children is thought to be caused by a defect in the satiety center in the hypothalamus. Stringent caloric restriction is the only known treatment. Laurence-Moon-Biedl (Bardet-Biedl) syndrome is transmitted as an autosomal recessive trait. Obesity, mental retardation, hypogonadism, polydactyly, and retinitis pigmentosa with night blindness are the principal findings in affected children. There is no known effective treatment. Fröhlich syndrome, also known as adiposogenital dystrophy, is a rare cause of childhood obesity associated with a hypothalamic tumor. Pseudohypoparathyroidism is a collective term for a variety of diseases. Affected patients have biochemical findings (low serum calcium and high serum phosphorus levels) similar to those associated with hypoparathyroidism, but they also have high levels of endogenous parathyroid hormone; in addition, exogenous parathyroid hormone fails to increase their phosphate excretion or raise their serum calcium level. The defects in these patients appear to be at the hormone receptor site or in the adenylate cyclase-cyclic AMP system. The symptoms of pseudohypoparathyroidism are caused by hypocalcemia. Affected children are short, round-faced, and mildly retarded. Metacarpals and metatarsals are shortened, and subcutaneous and basal ganglia calcifications as well as cataracts can be present. The current treatment consists of large doses of vitamin D and reduction of the phosphate load. Polycystic ovary disease classically presents at or shortly after puberty with obesity, hirsutism, and secondary amenorrhea. Later, these women have anovulatory infertility. The cause of this condition is not entirely clear. The initial complaint in Cushing syndrome may be obesity. Accumulation of fat in the face, neck, and trunk causes the characteristic "buffalo hump" and "moon" facies. Characteristic features include growth failure, muscle wasting, thinning of the skin, plethora, and hypertension. The bone age of affected patients is retarded, and osteoporosis can be present. The disorder results from an excess of glucocorticoids that may be caused by a primary adrenal abnormality (adenoma or carcinoma) or secondary hypercortisolism, which may be owing to excess adrenocorticotropin. Exogenous glucocorticoids administered in supraphysiologic doses for a prolonged period of time will produce a similar picture in normal subjects. The answer is G.
