Expanding the Spectrum of Methylmalonic Acid-Induced Pallidal Stroke: First Reported Case of Metabolic Globus Pallidus Stroke in Transcobalamin II Deficiency

Transcobalamin II 775G>C polymorphism and indices of vitamin B12 status in healthy older adults

Blood ◽

10.1182/blood-2002-01-0209 ◽

2002 ◽

Vol 100 (2) ◽

pp. 718-720 ◽

Cited By ~ 86

Author(s):

Joshua W. Miller ◽

Marisa I. Ramos ◽

Marjorie G. Garrod ◽

Margaret A. Flynn ◽

Ralph Green

Keyword(s):

Older Adults ◽

Vitamin B12 ◽

Functional Status ◽

Methylmalonic Acid ◽

Transport Protein ◽

Total Serum ◽

Healthy Older Adults ◽

Common Polymorphism ◽

B12 Deficiency ◽

Transcobalamin Ii

Abstract A common polymorphism (775G>C) in the vitamin B12 transport protein, transcobalamin II (TCII), has been identified in which proline replaces arginine at codon 259. We determined the influence of TCII genotype on indices of B12 status, including total serum B12, the amount of B12 bound to TCII (holoTCII), methylmalonic acid, and homocysteine, in 128 healthy older adults (ages 40-88 years). Mean total B12 and homocysteine concentrations were not significantly different among the 3 genotypes. Mean holoTCII concentration was significantly higher in those subjects homozygous for the proline form of TCII (PP) compared with those homozygous for the arginine form (RR) and heterozygotes (PR) (P ≤ .006). In addition, mean methylmalonic acid concentrations were significantly lower in the PP and PR groups compared with the RR group (P ≤ .02). The PP genotype may be more efficient in delivering B12 to tissues, resulting in enhanced B12 functional status. TCII genotype may thus influence susceptibility to B12 deficiency.

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Serum Vitamin B12 Concentrations among Mothers and Newborns and Follow-up Study to Assess Implication on the Growth Velocity and the Urinary Methylmalonic Acid Excretion

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831.79.56.297 ◽

2009 ◽

Vol 79 (56) ◽

pp. 297-307 ◽

Cited By ~ 3

Author(s):

Laila Hussein ◽

Sahar Abdel Aziz ◽

Salwa Tapouzada ◽

Boehles

Keyword(s):

Early Diagnosis ◽

Growth Velocity ◽

Methylmalonic Acid ◽

Post Partum ◽

Serum Vitamin ◽

Vitamin B ◽

Postnatal Life ◽

Negative Consequences ◽

Metabolic Marker ◽

Biochemical Measurement

Objective:Cobalamin (B12) deficiency has been reported in infants born to mothers with low cobalamin intake. Early diagnosis of vitamin B12 deficiency in infants is critical for the prevention of neurobehavioral disorders. We investigated the relationship between serum vitamin B12 level in newborns and in their healthy mothers who consumed an omnivorous diet. Anthropometry was studied longitudinally to assess the growth velocity of the infants. Urinary methylmalonic acid (MMA) excretion of 6-month old infants was compared retrospectively as the biomarker correlated with the initial serum vitamin B12 concentrations. Methods: Serum cobalamin and blood hemoglobin were determined in 84 pairs of newborns and their mothers. Urinary MMA excretion was measured in the same subjects during the first 6 months of the post partum period. Results: At birth, median serum cobalamin levels were 152.0 pmol/L in the mothers and 296.6 pmol/L in the newborns. Maternal and neonatal serum cobalamin levels had no effect on growth velocity during the first six months of postnatal life. Serum maternal and neonatal cobalamin levels were inversely associated with urinary MMA excretion. Conclusion: Early diagnosis of vitamin B12 status in neonates and infants is crucial, particularly in nutritionally deprived areas. Biochemical measurement of plasma cobalamin or its metabolic marker MMA is highly recommended. Urinary MMA measurement in cobalamin diagnostics provides an advantage in that blood sampling is not required. A vitamin B12 taskforce should be created to alleviate vitamin deficiency and its negative consequences.

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