SLC12A2 mutations cause NKCC1 deficiency with encephalopathy and impaired secretory epithelia

OBJECTIVE: To describe the phenotype in 2 sisters with a rare constellation of neurologic symptoms and secretory impairments and to identify the etiology by the use of whole-genome sequencing (WGS). METHODS: After an extensive workup failed to reveal the cause of disease, in a girl with a previously not reported phenotype, WGS of the proband, her diseased older sister, an older healthy brother, and their parents was performed, and potentially pathogenic variants were analyzed. RESULTS: were identified that follow an autosomal recessive inheritance pattern. CONCLUSIONS: as causing human disease and adds data regarding the neurologic phenotype.