A case of hyperphosphatemic familial tumoral calcinosis due to maternal uniparental disomy of a GALNT3 variant.

ABSTRACT: Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare, inherited autosomal recessive disorder caused by fibroblast growth factor-23 (FGF23), N-acetylgalactosaminyltransferase 3 (GALNT3), or Klotho (KL) gene variants. Here, we report the case of a Japanese boy who presented with a mass in his left elbow at the age of three. Laboratory test results of the patient revealed normocalcemia (10.3 mg/dL) and hyperphosphatemia (8.7 mg/dL); however, despite hyperphosphatemia, serum intact FGF23 level was low, renal tubular reabsorption of phosphate (TRP) level was inappropriately increased, and 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) level was inappropriately normal. Genetic analysis revealed maternal uniparental disomy (UPD) of chromosom

SUBMITTER: Nishimura-Kinoshita N 

PROVIDER: S-EPMC10288290 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature