A severe presentation of vitamin D-dependent hypocalcemic rickets associated with hypophosphatemia

This is a case report of a seven-year-old girl evacuated from Sao Tome and Principe due to rickets. She started walking at age 3, was unable to walk since age 4, and had recurrent episodes of respiratory distress¹. At physical examination, she was malnourished, had bell-shaped thorax, deformed and varus limbs, and missing teeth. Blood tests revealed severe hypocalcemia (6.4 mg/dL) and hypophosphatemia (2.5 mg/dL), high alkaline phosphatase (4161 U/L) and parathyroid hormone (509.6 pg/ml), normal range 25-hydroxyvitamin D; 1,25-dihydroxyvitamin D was not performed. Genetic study identified mutations in both CYP27B1² gene copies, leading to alterations in alpha-1-hydroxylase function. A diagnosis of vitamin-D-dependent rickets type 1A was made.

Figure 1
Patient radiographies showing severe bone deformities, pseudo-fractures in upper and lower limbs, and a bell-shaped thorax.

REFERENCES

• ¹
  Maia MLA, Abreu ALS, Nogueira PCK, Val MLDMD, Carvalhaes JTA, Andrade MC. Hypophosphatemic rickets: case report. Rev Paul Pediatr. 2018;36(2):242–7. doi: http://dx.doi.org/10.1590/1984-0462/;2018;36;2;00009. PubMed PMID: 29617471.
  » https://doi.org/10.1590/1984-0462/;2018;36;2;00009
• ²
  Kim YM, Jang YY, Jeong JE, Park HJ, Jang JH, Kim JK. A case of vitamin D hydroxylation-deficient rickets type 1A caused by 2 novel pathogenic variants in CYP27B1 gene. Ann Pediatr Endocrinol Metab. 2019;24(2):137–41. doi: http://dx.doi.org/10.6065/apem.2019.24.2.137. PubMed PMID: 31261480.
  » https://doi.org/10.6065/apem.2019.24.2.137

Publication Dates

• Publication in this collection
  06 Oct 2023
• Date of issue
  Jul-Sep 2023

History

• Received
  12 Apr 2023
• Accepted
  26 June 2023