Donohue syndrome, also known as leprechaunism, is a rare autosomal recessive form of insulin resistance syndrome with a distinctive phenotype including elfin facies and severe disturbances of glucose homeostasis. It is universally fatal in early childhood.

Epidemiology

Donohue syndrome is very rare with a prevalence estimated at 1 in 4 million live births, usually consanguineous offspring. Globally, there have been only 100 reported cases ¹.

Almost no cases survive beyond early infancy (under 3 years).

Clinical presentation

• elfin facial features

  • enlarged ears which are set low

  • a flattened nose

  • thick lips

  • orbital hypertelorism

• endocrine disturbances

  • severe growth restriction

  • altered carbohydrate metabolism, postprandial hyperglycemia

  • lipoatrophy

  • acanthosis nigricans

  • hypertrichosis, hirsutism

  • organomegaly

  • penile and clitoral enlargement

Pathology

Genetics

Donohue syndrome is caused by mutations in the INSR gene which codes for the insulin receptor which mediates the effects of insulin on cells ⁵.

History and etymology

This syndrome was originally described by the pediatric pathologist William Leslie Donohue in Toronto in 1948 when he coined the inaccurate term "dysendocrinism" for his novel cases. He published further on it in 1954 with his colleague, the medical geneticist Irene Uchida, when they used the term "leprechaunism" for the same disorder ^1-4.

A leprechaun is a diminutive elf-like creature found in Irish myth. The facial phenotype of Donohue syndrome is said to be evocative of leprechauns, hence the alternative monicker for this condition ¹.