Abstract
Andersen–Tawil syndrome, a potassium ion channelopathy, is caused by mutations in
the KCNJ2 gene, and accounts for approximately 10% of channelopathies. Phenotype is variable.
An 11-year-old boy presented with periodic paralysis without localizing neurological
signs, associated in only two of three occasions with hypokalemia, on a background
of a diagnosis of attention deficit hyperactivity disorder and autism spectrum disorder.
There was a history of syncope and palpitations. This was a matter of diagnostic uncertainty
due to the difficulty in interpreting his neurological signs, and inconsistency of
abnormal potassium levels. In children/young people with recurrent episodes of weakness
without localizing signs on physical examination, and syncope, the possibility of
a channelopathy should be considered, even in the absence of serum electrolyte abnormalities.
There is a possible link between KCNJ2 mutations and difficulties in attention and a specific neurocognitive profile.
Keywords
KCNJ2
- Andersen–Tawil syndrome - potassium ion channelopathy - hypokalemic periodic paralysis
