A novel variant in the SLC12A1 gene in two families with antenatal Bartter syndrome.

Aim Bartter syndrome is an autosomal recessive inherited disease in which patients present with hypokalaemia and metabolic alkalosis. We present two apparently non-related cases with antenatal Bartter syndrome type I, due to a novel variant in the SLC12A1 gene encoding the bumetanide-sensitive sodium-(potassium)-chloride cotransporter 2 in the thick ascending limb of the loop of Henle. Methods Blood samples were received from the two cases and 19 of their relatives and deoxyribonucleic acid was extracted. The coding regions of the SLC12A1 gene were amplified using polymerase chain reaction, followed by bi-directional direct deoxyribonucleic acid sequencing. Results Each affected child in the two families were homozygous for a novel inherited variant in the SLC12A1gene, c.1614T>A. The variant predicts a change from a tyrosine codon to a stop codon (p.Tyr538Ter). The two cases presented antenatally and at six months of age, respectively. Conclusion The two cases were homozygous for the same variant in the SLC12A1 gene, but presented clinically at different ages. This could eventually be explained by the presence of other gene variants or environmental factors modifying the phenotypes. The phenotypes of the patients were similar to other patients with antenatal Bartter syndrome. This article is protected by copyright. All rights reserved.