The Faeroe Islands has a high incidence of glycogen storage disease type III A, carnitine transporter deficiency and holocarboxylase synthetase deficiency. In the article the incidence, symptoms and gene mutations for these three inborn errors of metabolism are reviewed both in general and in specific for children in the Faeroe Islands. None of the mutations for the three diseases is particularly frequent, but all children in the Faeroe Islands with one of the three metabolic diseases are homozygous for one specific mutation, which must be due to a founder effect.