Inheritance: autosomal recessive, with most patients compound heterozygotes. Many patients have affected siblings.
Molecular defect: Affected patients have a defect in the gene that encodes mevalonate kinase (chromosome 12q24). A homozygous deficiency in mevalonate kinase results in mevalonic aciduria.
Racial groups affected: Dutch, French, other Western European countries
Onset: during infancy (age < 1 year)
Duration of attacks: lifelong, although more common in childhood and adolescence
The typical febrile attack usually lasts 4 to 6 days.
Attacks may be triggered by minor trauma, stress or vaccination.
Clinical features:
(1) initially a chill, followed by the onset of fever
(2) cervical lymphadenopathy
(3) abdominal pain
(4) diarrhea
(5) vomiting
(6) arthritis and/or arthralgias
(7) headache
(8) skin rash (erythematous macules, papules, petechiae and/or purpura
(9) hepatosplenomegaly
Laboratory findings:
(1) polyclonal elevation of IgD, often marked (> 100 IU/mL). Some patients may show only low levels
(2) often an increase in IgA
(3) during an attack the patient shows leukocytosis and an increased C reactive protein
