Dahlberg syndrome: A rare condition characterized by hypoparathyroidism, nephropathy, congenital lymphedema, mitral valve prolapse and short end bones in fingers and toes.
* Broad nasal bridge * Displacement of inner canthi * Congenital lymphedema * Hypoparathyroidism * Nephropathy
Hypoparathyroidism may be acute or chronic and is classified as idiopathic or acquired. The acquired form may also be reversible. Idiopathic hypoparathyroidism may result from an autoimmune genetic disorder or the congenital absence of the parathyroid glands. Acquired hypoparathyroidism commonly results from accidental removal of or injury to one or more parathyroid glands during thyroidectomy or other neck surgery; rarely it results from massive thyroid irradiation. It may also result from ischemic infarction of the parathyroids during surgery or from hemochromatosis, sarcoidosis, amyloidosis, tuberculosis, neoplasms, or trauma. An acquired, reversible hypoparathyroidism may result from hypomagnesemia-induced impairment of hormone synthesis, from suppression of normal gland function due to hypercalcemia, or from delayed maturation of parathyroid function. (See What happens in acute hypoparathyroidism.) PTH isn’t regulated by the pituitary or hypothalamus. It normally maintains blood calcium levels by increasing bone resorption and GI absorption of calcium. It also maintains an inverse relationship between serum calcium and phosphate levels by inhibiting phosphate reabsorption in the renal tubules. Abnormal PTH production disrupts this balance. The incidence is 4 out of 100,000 people. Incidence of the idiopathic and reversible forms is highest in children; that of the irreversible acquired form, in older patients who have undergone surgery for hyperthyroidism or other head and neck conditions.