A case report of Hyper-IgD syndrome in a 5-year-old girl with recurrent fever, skin rash, and arthralgia; novel MVK mutation (C.298G>A)

Key Clinical Message This case highlights the potential for later-onset Hyper-IgD syndrome (HIDS) even beyond infancy. Clinicians evaluating children with recurrent fever, skin rash, and arthralgia should consider HIDS in the differential diagnosis, regardless of age. Early suspicion and genetic testing can lead to a timely diagnosis and targeted therapy with Anakinra, significantly improving patient outcomes. Hyper-IgD syndrome (HIDS) is a rare autosomal recessive autoinflammatory disorder characterized by recurrent episodes of fever, lymphadenopathy, arthralgia, diarrhea, abdominal pain, and skin rash. In this case report, we present a 5-year-old girl from Tajikistan with a mutation in the mevalonate kinase (MVK) gene, which is consistent with a diagnosis of HIDS. The clinical symptoms of the patient are described, along with immunological, hematological, and biochemical findings collected from the evaluation in the rheumatology clinic. Additionally, whole-exome sequencing revealed a heterozygous missense variation in exon 4 of the MVK gene. The diagnosis of HIDS in this case occurred at a later age than typically observed, emphasizing the importance of considering this condition even in older patients. This report highlights the broad clinical phenotype of MVK and the need for increased awareness among healthcare professionals regarding its clinical presentation and management.