Vitamin B12 deficiency with intrinsic factor antibodies in an infant with poor growth and developmental delay

Area of Science:

• Pediatrics
• Hematology
• Nutritional Science

Background:

• Vitamin B12 deficiency is uncommon in infants but can cause severe hematological and neurodevelopmental issues.
• Juvenile pernicious anemia is a rare cause of vitamin B12 deficiency in children.

Observation:

• A seven-month-old boy presented with feeding intolerance, poor growth, and developmental delay.
• Clinical findings included macrocytic anemia, low serum vitamin B12, elevated homocysteine and methylmalonic acid, and positive intrinsic factor antibodies.

Findings:

• The infant's condition was diagnosed as severe vitamin B12 deficiency, likely due to juvenile pernicious anemia.
• The child's mother had normal vitamin B12 levels, suggesting an idiopathic cause in the infant.

Implications:

• This case highlights the importance of considering vitamin B12 deficiency in infants with failure to thrive and neurological symptoms.
• Prompt diagnosis and vitamin B12 therapy are essential to prevent irreversible hematological and neurodevelopmental complications in affected infants.