SLCO2A1 Gene Variant in a Portuguese Patient with Primary Hypertrophic Osteoarthropathy

Abstract

Primary hypertrophic osteoarthropathy is a rare disease characterized by three major clinical symptoms: pachydermia,
periostosis, and digital clubbing. Diagnosis of primary hypertrophic osteoarthropathy is based on clinical and radiographic
characteristics confirmed by genetic studies. A complete form of the syndrome is reported in a male patient, with disease
onset in adolescence. There were compatible clinical and radiological findings, presenting the three cardinal findings as well as other associated manifestations, such as hyperhidrosis and acne. A genetic study revealed an apparently homozygous variant in the SLCO2A1 gene, c.644C>T, in the exon 12, which causes the exchange of the highly conserved amino acid serine by a phenylalanine in 215 position in the protein. To the best of our knowledge, the homozygosity of this variant has not yet been described in disease databases, such as ClinVar, and it constitutes the first genetically confirmed case of primary hypertrophic osteoarthropathy in a Portuguese patient.