||common in clinvar
||LQT1 form of Long QT syndrome
||LQT1 form of Long QT syndrome; Jervell and Lange-Nielsen syndrome
rs17215500 represents two variants in the KCNQ1 gene on chromosome 11; a c.1552C>T change (also known as p.Arg518Ter or R518X), and a c.1552C>G change (also known as p.Arg518Gly or R518G).
The c.1552C>G variant is reported as a variant of unknown significance in ClinVar; although it is very rare and has only been reported in several individuals with Long QT syndrome type 1, the available evidence is not considered sufficient to conclude if it is disease-causing.
The c.1552C>T variant, on the other hand, is considered pathogenic for Long QT syndrome as either a dominant or perhaps recessive mutation, and, for Jervell and Lange-Nielsen syndrome, a form of Long QT syndrome that is inherited recessively and associated with hearing loss from birth. In the absence of other pathogenic KCNQ1 gene mutations, the c.1552C>T mutation results in variable expressivity and may have reduced penetrance, depending on other genetic and environmental factors according to ClinVar.
23andMe name for the c.1552C>T variant: i3000206
[PMID 18852891] Distribution and effects of nonsense polymorphisms in human genes.
[PMID 16414944] Genetic testing in the long QT syndrome: development and validation of an efficient approach to genotyping in clinical practice.