Leprechaunism. Donohue syndrome.
Incidence
Very rare congenital disorder (less than 1 case in every million births) transmitted as an autosomal recessive trait.
Clinical Characteristics
Leprechaunism is a very rare congenital disorder (less than 1 case in every million births) transmitted as an autosomal recessive trait. It is marked by an intrauterine and mainly postnatal major growth retardation. It is associated with characteristic dysmorphic facies (resembling that of 'leprechauns' in the Irish folk traditions), atrophic subcutaneous adipose tissue (lipoatrophy) and muscular hypotrophy. Signs of virilization are often observed in little girls. Biologically, episodes of hypo- and hyperglycemia are observed along with marked hyperinsulinemia due to an extreme resistance to insulin. The following are very frequently observed signs: small face, thick lips, long/large ear, flared nostrils, hyperinsulinism, excess nuchal skin, recurrent infections, macropenis/large penis, proptosis/exophthalmos, short stature/dwarfism, wasted/poorly muscled build, autosomal recessive inheritance, gynecomastia/breast enlargement, hyperglycemia/diabetes mellitus, intrauterine growth retardation, difficulties for feeding in infancy, external female genitalia anomalies, mental retardation (moderate/severe), condition lethal in infancy/childhood. These signs were frequently found: delayed bone age, increased body hair, depressed nasal bridge. The following signs were seen occasionally: icterus, microcephaly, inguinal hernia, umbilical hernia, high vaulted/narrow palate, undescended/ectopic testes, absent/diminished abdominal musculature. Prognosis is uncertain, growth is severely affected and life span rarely exceeds a few months. From a genetic viewpoint, mutations in the insulin receptor gene have to be searched for. Caused by mutations in the insulin receptor gene (INSR). Treatment with recombining IGF 1 may be considered.
Precipitants
none
Provocation Tests
none
Diagnostic Procedures
Elevated plasma insulin. Absent anti-insulin receptor antibodies. Postprandial hyperglycemia. Fasting hypoglycemia.