What are causes of hypoparathyroidism?

Iatrogenic (most common cause is excision of all parathyroid glands via surgery treating thyroid/largeal/ neck malignancy, extensive irradiation to face/neck/mediastinum also could cause it) Autoimmune (type 1 polyglandular syndrome (HAM syndrome) destroys parathyroid and adrenals, develop by age 10 years, may exist alone or in familial forms, average of development of hypocalcemia is 7 years range 6 months to 20 years) Congenital causes (numerous causes for agenesis/ hypoplasia thus at birth symptomatic hypocalcemia) Causes related to metal overload/ion deficiency (hemochromatosis/ thalassemia, Wilson, Aluminium deposits w/in parathyroid in end-stage renal disease, hypermagnesemia and hypomagnesemia) Infiltration of parathyroid glands (metastasis, granulomatous disease, amyloidosis, syphilis, progressive systemic scleosis) Neonatal causes (mother w/hypercalcemia supress baby PTH become atrophic glands w/in first 3 weeks of birth we see hypopara but self-limited