Objectives: VEXAS syndrome is an autoinflammatory disease associated with a somatic mutation of the X-linked UBA1 gene in haematopoietic progenitor cells. This disorder was originally described as a disease affecting men, but rare cases of VEXAS syndrome in women have since been reported. The theoretical existence of phenotypic sex differences in this X-linked disease is debated. We compared the features of VEXAS syndrome between males and females to better understand this disorder and to improve its diagnostic accuracy in females.
Methods: From previously published clinical descriptions of VEXAS syndrome, we included studies that described patients with precise, individual VEXAS-related features. We formed a literature-based cohort of patients by collecting their clinical and biological data and compared the characteristics of male and female patients.
Results: We gathered 224 patient descriptions from 104 articles: 9 women and 215 men. Among the women, 1 had a constitutional 45, X karyotype and 4 had an acquired X monosomy in the bone marrow karyotype, while the marrow karyotype was not provided for the others. No difference was observed in the clinical or biological features according to sex. We also observed no difference in the type of UBA1 mutation or the association with myelodysplastic syndrome.
Conclusions: Our results supported that UBA1 mutation should be sought under the same conditions in both sexes. As UBA1 is not subject to X-chromosome inactivation, VEXAS syndrome in females requires both UBA1 mutation and X monosomy, thus explaining the similarity between male and female VEXAS-related features and the lower prevalence of VEXAS syndrome in females.
Keywords: UBA1 gene; VEXAS syndrome; X-linked gene; autoinflammation; women.
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