FROM "INFANTILE" TO ELDERLY: A RARE CAUSE OF HYPERCALCEMIA NOT TO BE MISSED IN THE GERIATRIC POPULATION


BAŞ AKSU Ö., Güngör H., Leblebici C., KUTLAY N., ERDOĞAN M. F.

Acta Endocrinologica, cilt.21, sa.2, ss.272-276, 2025 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 21 Sayı: 2
  • Basım Tarihi: 2025
  • Doi Numarası: 10.4183/aeb.2025.272
  • Dergi Adı: Acta Endocrinologica
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE
  • Sayfa Sayıları: ss.272-276
  • Anahtar Kelimeler: CYP24A1, Hypercalcemia, Vitamin D Metabolism
  • Ankara Üniversitesi Adresli: Evet

Özet

Idiopathic infantile hypercalcemia (IIH) is a rare, parathyroid hormone (PTH)–independent disorder of calcium metabolism. It is most often caused by mutations in the CYP24A1 gene that impair vitamin D catabolism. We report a 70-year-old male with persistent hypercalcemia (Ca 13.2 mg/dL) and low-normal PTH levels. Extensive evaluation excluded malignancy, granulomatous disease, and vitamin D intoxication. Genetic analysis revealed a homozygous CYP24A1 variant (c.233G>T; p.Gly78Val), consistent with CYP24A1 deficiency. Bisphosphonate therapy with zoledronic acid rapidly and sustainably normalized calcium levels for 10 months. The patient’s daughter was a heterozygous carrier. This confirmed autosomal-recessive inheritance. This case illustrates an atypical late-onset presentation of CYP24A1 deficiency. It emphasizes the importance of considering this diagnosis in adults with PTH-independent hypercalcemia, especially when seasonal variation and family history are present. Recognition of CYP24A1 deficiency at all ages highlights the need for genotype-based terminology rather than the misleading label "infantile" hypercalcemia.