Introduction: In infants, vitamin B12 deficiency is mainly due to nutritional deficiencies related to maternal deficit. Most cases of maternal deficiencies are associated with vegetarian diets. Pernicious anemia is an au toimmune disease that affects the absorption of this vitamin. Although it is less common than nutri tional deficiency, is also an important cause of maternal deficiency.
Objective: to report a case of an infant with vitB12 deficiency, secondary to pernicious anemia in his mother, and to review the most important aspects of this disease in childhood.
Clinical case: Nine months-old male infant, without pathological perinatal history, exclusively breastfed, with persistent rejection of solid food from 6 months of age. One month before hospitalization, he progressively presented hyporesponsiveness, with fluctuating state of alertness, regression of motor development milestones, and vomiting. The blood count showed macrocytic anemia and neutropenia. Vitamin B12 deficiency was confirmed in the patient. He received treatment with intramuscular vitamin B12 with good clinical and laboratory response. Maternal B12 deficiency was confirmed as the cause of the infant's deficiency. Since the mother reported no dietary restrictions, anti-intrinsic factor and anti-parietal cell antibodies were measured, leading to the diagnosis of pernicious anemia.
Conclusions: Early recognition is essential to prevent the development of potentially irreversible neurological damage. Maternal pernicious ane mia should be considered in children with megaloblastic anemia, especially in those whose mothers do not follow vegetarian diets.