Clinodactyly and syndactyly – diagnostic clues for Andersen-Tawil syndrome

Clinodactilia e sindactilia – pistas diagnósticas da síndrome de Andersen-Tawil

A 38-year-old man was diagnosed, at the age of 18, with SCN4A-negative hyperkalaemic periodic paralysis. The diagnosis remained unchanged until his 8-year-old daughter suffered an exercise-induced syncope. Her EKG showed a polymorphic ventricular tachycardia. Patient's hands and feet, previously overlooked, became “neurologically” relevant since they were characteristic of Andersen-Tawil syndrome (Figure). A pathogenic KCNJ2 mutation (Arg218Trp) was found.

Figure
(A) Fifth digit clinodactyly and (B) syndactyly of the toes 2 and 3, highly suggestive of Andersen-Tawil syndrome. The face (not shown) had only mild phenotypical characteristics.

Andersen-Tawil syndrome is an autosomal dominant disorder characterized by the triad of periodic paralysis, ventricular arrhythmias, and dysmorphic features¹. Phenotypical heterogeneity, even within a family, often delays the diagnose which is necessary since cardiac assessment is warrant².

References

• ¹
  Tawil R, Ptacek LJ, Pavlakis SG, DeVivo DC, Penn AS, Ozdemir C et al. Andersen's syndrome: potassium-sensitive periodic paralysis, ventricular ectopy, and dysmorphic features. Ann Neurol. 1994;35(3):326-30. http://dx.doi.org/10.1002/ana.410350313
  » https://doi.org/10.1002/ana.410350313
• ²
  Davies NP, Imbrici P, Fialho D, Herd C, Bilsland LG, Weber A, et al. Andersen-Tawil syndrome: new potassium channel mutations and possible phenotypic variation. Neurology. 2005;65:1083-9.

Publication Dates

• Publication in this collection
  Nov 2014

History

• Received
  14 June 2014
• Reviewed
  31 July 2014
• Accepted
  19 Aug 2014