Thiamine metabolism dysfunction syndrome 5 (THMD5) is an uncommon subtype of the disorders due to mutations in TPK1 (coding for thiamine pyrophosphokinase 1, TPK1), which was first described in five patients from three families by Mayr JA et al. in 2011 [2]. This evidence concerns the gene TPK1 and childhood encephalopathy due to thiamine pyrophosphokinase deficiency.