Mevalonic Aciduria

Mevalonic aciduria (MEVA) is a rare genetic disorder identified as the first defect in cholesterol and non-sterol isoprene biosynthesis by Hoffmann et al. in 1986. Hoffmann et al. (1986) described this inborn error of cholesterol metabolism in a two-year-old boy exhibited with significant failure to thrive, developmental delay, anemia, hepatosplenomegaly, central cataracts, and dysmorphic features (Hoffmann et al. 1986). Berger et al. (1985) described a milder case of this disorder with cerebellar ataxia (Berger et al. 1985). MEVA and hyperimmunoglobulinemia D syndrome (HIDS) represent the two extremes of a clinical spectrum of disease resulting from a deficiency of mevalonate kinase (MVK), the first enzyme involved in cholesterol biosynthesis (Haas and Hoffmann 2006). HIDS is a milder and more common type, while MEVA is a more severe and less common type (Zhang 2016). Mevalonate kinase deficiency (MKD) is characterized by recurrent inflammatory attacks, and abrupt onset of high fever (frequently exceeding 40 °C) is the main symptom that is noticed. Each episode of inflammatory attacks lasts 3–7 days in most patients. Febrile attacks occur spontaneously but can also be precipitated by vaccination, infection, or physical and emotional stressful situations. Febrile attacks occur irregularly every 2–8 weeks in HIDS patients and with more frequencies in MEVA patients than in HIDS patients, with the previous MEVA reporting as often as 25 episodes and the last mentioned HIDS averaging 12 annually (Zhang 2016).