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CASE REPORT article

Front. Immunol.

Sec. Autoimmune and Autoinflammatory Disorders: Autoinflammatory Disorders

Volume 16 - 2025 | doi: 10.3389/fimmu.2025.1651819

Mevalonate kinase deficiency: an underdiagnosed cause of ischemic stroke – characterization of a novel genetic variant

Provisionally accepted
Lyna-Nour  HamidiLyna-Nour Hamidi1Jack  Christopher DrdaJack Christopher Drda2Meriem  BelhocineMeriem Belhocine3,4Hannah-Laure  ElfassyHannah-Laure Elfassy3Stéphanie  Ducharme-BénardStéphanie Ducharme-Bénard3Maxime  Chayer-LanthierMaxime Chayer-Lanthier5Bushra  SultanaBushra Sultana3Sylvain  LanthierSylvain Lanthier3*
  • 1McGill University Department of Genetics, Montreal, Canada
  • 2University of Pittsburgh School of Medicine, Pittsburgh, United States
  • 3Hopital du Sacre-Coeur de Montreal, Montreal, Canada
  • 4Faculty of Medicine, Universite de Montreal, Montreal, Canada
  • 5Universite de Sherbrooke, Sherbrooke, Canada

The final, formatted version of the article will be published soon.

Mevalonate kinase deficiency (MKD) is an inherited autoinflammatory syndrome resulting from impaired isoprenoid biosynthesis due to biallelic mevalonate kinase (MVK) mutations. This metabolic defect leads to dysregulated innate immunity, particularly excessive interleukin-1β release. While typically presenting in childhood with periodic fevers, expanding evidence links MKD to heterogeneous adult phenotypes with immune-mediated end-organ damage. We report an adult male presenting with leg pain and finger cyanosis followed by acute ischemic stroke, macular rash, and lymphadenopathies. He exhibited classical markers of innate immune activation, including persistent elevation of C-reactive protein. Genetic testing identified compound heterozygosity for the known MVK pathogenic variant c.1129G>A (V377I) and a novel missense variant, c.1049A>C (Q350P). Structural modeling of Q350P revealed disruption of the GHMP kinase domain, predicted to destabilize mevalonate kinase conformation and impair its function. Measurement of mevalonate kinase activity in lymphocytes was at 55% (normal >60%). Interleukin-1β blockade with canakinumab was initiated, and blood markers of inflammation normalized, further supporting a central role for innate immune dysregulation. This case highlights a novel MVK missense variant (Q350P) with subnormal mevalonate kinase activity. The patient's compound heterozygous state with partially preserved mevalonate kinase activity may explain the attenuated systemic features and the delayed clinical onset. Remarkably, ischemic stroke was part of the initial presentation, suggesting that mevalonate kinase deficiency can manifest primarily through thrombo-inflammatory complications in adulthood, even in the absence of recurrent febrile episodes. This expands the phenotypic spectrum of MKD and underscores the need to consider adult-onset autoinflammatory syndromes in the differential diagnosis of cryptogenic ischemic strokes with markers of systemic inflammation. It also supports the utility of cytokine-targeted therapies in such contexts.

Keywords: auto-inflammation, ischemic stroke, Mevalonate Kinase Deficiency, Neuroinflammation, vasculopathy

Received: 03 Jul 2025; Accepted: 12 Sep 2025.

Copyright: © 2025 Hamidi, Drda, Belhocine, Elfassy, Ducharme-Bénard, Chayer-Lanthier, Sultana and Lanthier. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Sylvain Lanthier, sylvain.lanthier@umontreal.ca

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