Gitelman's syndrome presenting with hypocalcaemia, basal ganglia calcification and periodic paralysis

Gitelman's syndrome (GS), also referred to as familial hypokalaemia-hypomagnesaemia syndrome, is an autosomal recessive renal tubular disorder characterised by hypokalaemic metabolic alkalosis, hypomagnesaemia and hypocalciuria. It is caused by a defect of the thiazide-sensitive sodium chloride co-transporter at the distal tubule. This condition was previously confused with Bartter syndrome. Documentation of hypocalciuria helps to differentiate GS from Bartter syndrome. We report a 44-year-old woman who presented with a history of seizure disorder and periodic paralysis. On investigation, she was found to have hypokalaemic metabolic alkalosis, hypomagnesaemia, hypocalciuria, hypoparathyroidism, hypocalcaemia and basal ganglia calcification, consistent with GS. The atypical features in our case, namely basal ganglia calcification and hypocalcaemia, prompted the writing of this case report.