[Hyperimmunoglobulinemia D and periodic fever syndrome]. / Le syndrome d'hyper-immunoglobulines D (HIGDS) avec fièvre périodique. À propos de deux observations.

We report the cases of two sisters born of parents who were first-degree cousins, who started recurrent fever with lymph node and digestive tract involvement at the age of 2 years. There was no mutation of the familial Mediterranean fever gene and a diagnosis of partial mevalonate kinase (MVK) deficiency was made. However, immunoglobulin (Ig) D and A levels were normal. Elevated mevalonic acid in the patients' urine during an episode and MVK gene analysis provided the diagnosis. Clinical remission was obtained under anti-TNF-alpha treatment with etanercept. These observations and those of several previously reported patients, particularly in French and Dutch series, illustrate the importance of considering the diagnosis in a child with early-onset auto-inflammatory syndrome even in the absence of hyper-IgD or -IgA.