VIT. B12 DEFICIENCY IN CHILDREN (IMERSLUND-GRÄSBECK SYNDROME IN TWO PAIRS OF SIBLINGS).Dev Period Med. 2015 Jul-Sep; 19(3 Pt 2):351-5.DP
Improvement in the quality of life in Europe and North America in last decades caused that economical and social aspects of living conditions of the population have less effect and genetic defects of malabsorption of vitamin B12 became the main reason for cobalamin deficiency in children. Imerslund-Grasbeck syndrome (IGS) is characterized by vitamin B12 deficiency that leads usually to megaloblastic anemia and mild proteinuria. We described two pairs of siblings in two families with IGS. The diagnosis in first family (two brothers) was established at 33 and 22 months of age. The reason for diagnostic tests were proteinuria and anemia. Apart from respiratory tract infections, they didn't present other symptoms of cobalamin deficiency. In the second family IGS was diagnosed in children at 5 and 8 years of age. Diagnostic evaluation procedures wereperformedbecause ofneurologicalsigns, including weakness, loss of appetite, dysmorphia, psychomotor retardation. Laboratory tests revealed megaloblastic anemia, low concentration of vitamin B12 in serum and mild proteinuria. In the first pair low concentration of vitamin B12 was validated by the Schilling test, in the second pair methylomalonate acid was detected in the urinary metabolic test. All children were successfully treated with vitamin B12 and anemia and neurological signs disappeared. Long-term follow up showed failure to thrive in the girl and physical and mental retardation, microcephaly in her brother. Proteinuria in the range: 0.3-1.2 g/24 h was detected in each child, and the other laboratory tests were normal. Clinical symptoms, laboratory tests and good reaction to parenteral treatment with vitamin B12 allowed us to diagnose Imerslund-Grasbeck syndrome, even without genetic tests.
A delayed diagnosis of congenital malabsorption of cobalamin can lead to physical and mental retardation in children. Children with megaloblastic anemia and proteinuria resistant to classical treatment should be tested for congenital malabsorbtion of cobalamin.