1. The case is described of a child with retarded physical and mental development, recurrent
megaloblastic anaemia, methylmalonic aciduria and abnormal homocysteine metabolism …

In humans, the B 12 coenzymes, adenosylcobalamin and methylcobalamin, are required
cofactors for propionate metabolism and methionine biosynthesis, respectively. Humans are …

A male infant with methyl‐B12 deficiency (cblE) presented at age 6 weeks with lethargy,
staring spells, and vomiting. He later became hypotonic and unrespon sive to stimuli and …

Background Over the last forty years, our laboratory has accumulated a collection of over
1000 cultured fibroblast lines derived from patients from around the world referred with signs …

Deficient activity of an enzyme can result from a defect in the conversion of the vitamin to a
co-enzyme as well from an abnormal apo-enzyme or disturbed binding of co-enzyme to …

Patients with inherited disorders affecting cobalamin (Cbl) absorption or metabolism show
elevations of homocysteine or methylmalonic acid, either alone or in combination. For those …

The metabolism of vitamin B~ 2 by mammalian cells is complex, involving endocytosis of
vitamin Bt2 bound to plasma transcobalamin II, removal of the vitamin from the binding …

Vitamin BI2 in this review is defined as a group of cobalamin compounds that act as
intracellular coenzymes or that can be converted to these coenzyme forms by mammals. It …

Vitamin Br2 (cobalamin, Cbl) is required as a coenzyme for two reactions in mammalian
cells. One of these permits the efficient utilization of folate and the synthesis of methionine …

Inherited disorders of vitamin B 12 include those which involve the inability of the vitamin to
be absorbed from the gut and transported to the appropriate tissues, and those in which the …