Hypocalcemia due to tubular dysfunction in a patient with holoprosencephaly

Area of Science:

• Pediatric Endocrinology
• Neonatal Neurology
• Clinical Case Reports

Background:

• Holoprosencephaly is a congenital disorder affecting brain development.
• Hypocalcemia is a common complication in infants, especially those with underlying medical conditions.
• Vitamin D metabolism plays a crucial role in calcium homeostasis.

Observation:

• A female infant diagnosed with holoprosencephaly developed hypocalcemia 60 days post-birth.
• The hypocalcemia was attributed to decreased serum 1,25-dihydroxyvitamin D due to renal tubular dysfunction.
• Potential contributing factors included prerenal acute renal failure, anticonvulsant medication, and hypothyroidism.

Findings:

• Despite normal serum 25-hydroxyvitamin D levels and no signs of rickets, the infant exhibited significantly low 1,25-dihydroxyvitamin D.
• Treatment with high-dose 1alpha-hydroxyvitamin D3 and calcium lactate successfully normalized both calcium and 1,25-dihydroxyvitamin D levels.
• The infant's underlying renal tubular dysfunction and associated metabolic derangements were key to the hypocalcemia.

Implications:

• This case highlights the complex interplay between holoprosencephaly, renal function, and vitamin D metabolism in infants.
• It underscores the importance of monitoring calcium and vitamin D levels in infants with complex congenital anomalies and renal dysfunction.
• The successful normalization of vitamin D metabolites with targeted therapy suggests potential treatment strategies for similar cases, despite the ultimate poor prognosis.