KCNJ16 tubulopathy presenting with recurrent acute flaccid paralysis and sensorineural hearing loss.

A 13-year-old girl, born to third-degree consanguineous parents, presented with acute flaccid paralysis. There was a past history of a similar episode at 5 years of age. Her current laboratory investigations revealed hypokalemia and normal anion gap-metabolic acidosis. Pure tone audiometry showed bilateral sensorineural hearing loss (SNHL). There was no nephrocalcinosis, ataxia, or epilepsy. Whole exome sequencing detected a homozygous deletion (c.269_270del) in exon 4 of KCNJ16 gene that led to frameshift and premature truncation of the protein (p. Ser90CysfsTer15; ENST00000392671.6). She was managed with potassium citrate. KCNJ16 tubulopathy should be considered in the differential diagnosis of children presenting with metabolic acidosis, hypokalemia, and SNHL. In literature, clinical phenotypes of hypokalemic metabolic acidosis as well as salt-losing tubulopathies with hypokalemic metabolic alkalosis are described in this disorder. This is the first report of a child with p.Ser90CysfsTer15 homozygous frameshift KCNJ16 mutation, who presented with hypokalemia and metabolic acidosis, and had severe clinical manifestations.