Table 1 Admission and follow-up clinical and laboratory data of an infant with vitamin B12 deficiency
Parameter | Admission | Two weeks after admission | Three months after admission | Five months after admission | Seven months after admission |
|---|---|---|---|---|---|
Clinical data | |||||
Age, months | 5 | 6 | 8 | 10 | 12 |
Weight, g | 4,800 | 5,660 | 6,515 | 7,000 | 7,445 |
Length, cm | 60 | 61.5 | 65.5 | 67.5 | 69 |
Head circumference, cm | 39 | 42 | 43.5 | 45 | 46 |
Pathological clinical findings | Poor weight gain, feeding difficulties, severe pallor, muscle hypotonia, somnolence, enlarged liver and spleen | Persistence of hypotonia and mildly enlarged liver and spleen | Persistence of mild hypotonia and mildly enlarged liver and spleen | Persistence of mild hypotonia | Persistence of mild hypotonia |
Pathological neurological findings | Significant delay in developmental milestones and communicative reactions | Significant delay in developmental milestones and communicative reactions | Significant delay in developmental milestones and communicative reactions | Able to remain seated with delay in other developmental milestones and communicative reactions | Able to remain seated, delay in gross motor function and language; Griffith’s scale 86 (normal values, 92–100) |
Laboratory data | |||||
Hb, g/dL | 4.7 | 10 | n.a. | n.a. | 12.2 |
MCV, fL | 84.2 | 91.3 | n.a. | n.a. | 81.2 |
White blood cell count, cells/mm3 | 4,680 | 9,810 | n.a. | n.a. | 13,410 |
Platelet count, cells/mm3 | 45,000 | 492,000 | n.a. | n.a. | 375,000 |
Peripheral blood film | Oval macrocytes, anisopoikilocytosis, hypochromia, anisochromia, and hypersegmented polymorphonuclear leukocytes | Normal | n.a. | n.a. | Normal |
Bone marrow examination | Reduced number of red line cells with some megaloblasts; a small number of dysplastic megakaryocytes; dysplastic granulopoiesis with asynchronous maturation processes | n.a. | n.a. | n.a. | n.a. |
Serum vitamin B12, pg/mL | 57 | >2,000 | n.a. | n.a. | 1,344 |
Serum folic acid, ng/mL | 12.8 | 14 | n.a. | n.a. | 17.3 |
Serum iron, μg/dL | 9 | 76 | n.a. | n.a. | 73 |
Serum ferritin, ng/mL | 4 ng/mL | 31 | n.a. | n.a. | 49 |
Blood homocysteine, μmol/L | 11 | 5.4 | n.a. | n.a. | 2 |
Urinary methylmalonic acid, μmol/mol creatinine | 281 | 6 | n.a. | n.a. | 4 |
MMACHC gene mutations | None | n.a. | n.a. | n.a. | n.a. |
Neuroimaging | |||||
MRI | Mild dilatation of lateral ventricles with diffuse retarded myelination, most markedly in the brainstem | n.a. | n.a. | n.a. | Persistent mild dilatation of lateral ventricles with diffuse retarded myelination, most markedly in the brainstem |