A 17-year-old short-statured girl (figure 1) presented with seizures, progressive cataracts, and tetany. Further evaluation revealed positive Chvostek sign (video), cerebrostriothalamic calcifications or Fahr syndrome, persistent hypocalcemia (total serum calcium 6.5 [normal 9 -10.5] mg/100 mL), and primary hypoparathyroidism (serum parathyroid hormone Ͻ3.0 [normal 12-72] pg/mL).Chvostek sign, seen in hypocalcemia, hypomagnesemia, or alkalosis, is also reported in children with epilepsy. 1 Calcifications in Fahr syndrome (figure 2) are distinguishable from those of physiologic and other causes, including hyperparathyroidism; phacomatoses; gliosis from CNS infections, trauma, or strokes; and neoplasms. Clinically, Fahr syndrome can be associated with rigidity, seizures, psychosis, and dementia. Short stature and primary hypoparathyroidism prompted investigations for a mitochondrial disorder, 2 but a muscle biopsy was normal.