How do you test for KCNT2-related disorder?
The testing can be arranged by a paediatrician or a geneticist and involves a blood or saliva collection. The DNA is tested for changes in the DNA code of the KCNT2 gene. The changes identified are de novo, meaning that they are new changes found in affected individuals and neither parent is likely to be a carrier.
This is a genetic condition and is not related to environmental exposures or events during pregnancy or in early infant life. KCNT2-related disorder is caused by changes in the KCNT2 gene, which is located on chromosome 1. The KCNT2 gene belongs to a large family of genes that provide instructions for making potassium channels in the brain. These channels allow positively charged atoms (ions) of potassium into and out of cells, play a key role in a cell’s ability to generate and transmit electrical signals within the brain. “K” is the chemical symbol for potassium. Potassium channels are made up of several protein components (subunits). Each channel contains four alpha subunits that form the hole (pore) through which potassium ions move. The KCNT2 gene produces alpha subunits that form a potassium channel called the ‘Slo2’ or ‘SLICK’ channel. SLICK stands for ‘‘sequence like an intermediate conductance K+’’. Subunits made by the KCNT2 gene can also interact with subunits produced from the closely related KCNT1 gene to form functional potassium channels. Changes in the KCNT1 gene have also been described to cause genetic seizure disorders.
KCNT2-related seizure disorder is due to small ‘spelling mistakes’ in the gene that stop it from working properly.