Hereditary folate malabsorption

Methionine synthase deficiency (cobalamin-E disease) produces homocystinuria without methylmalonic aciduria 677 Cobalamin-c disease remethylation of homocysteine to methionine also requires an activated form of vitamin B12 677 Hereditary folate malabsorption presents with megaloblastic anemia, seizures and neurological deterioration 678... 

Hereditary folate malabsorption presents with megaloblastic anemia, seizures and neurological deterioration. 

Individuals affected with hereditary folate malabsorption exhibit early onset of failure to thrive, megaloblastic anemia, and severe mental retardation. Therapy requires the administration of large doses of oral and systemic folates. Folate is reduced and converted to N -methyltetrahydrofolate in intestines and secreted into the circulation. 

Inherited disorders of folate transport and metabolism include defects in folate carrier (hereditary folate malabsorption, previously discussed), deficiency of N, N °-methylene FH4 reductase (Chapter 17), or functional deficiency of N -methyl FH4 methyltransferase due to defects... 

Que A., et al. Identification of an intestinal folate transporter and the molecular basis for hereditary folate malabsorption. Cell 2006 127 917-28. 

The deficiencies of cystathionine )5-synthase (CBS), sulfite oxidase, and methylenetetrahydrofolate reductase (MTHFR) may all result in central nervous system dysfunction, in particular mental retardation [1-3]. Defects of CBS and sulfite oxidase both cause dislocated lenses of the eyes, but the phenotypes are different otherwise. The manifestations of CBS deficiency, the most common of these disorders, and MTHFR deficiency range from severely affected to asymptomatic patients both may cause vascular occlusion. Deficiency of sulfite oxidase is clinically uniform, but genetically heterogeneous, and functional deficiency of the enzyme can result from several inherited defects of molybdenum cofactor biosynthesis [2, 4]. Hereditary folate malabsorption and defects of cobalamin transport (transcobala-min II deficiency) or cobalamin cofactor biosynthesis (cblC-G diseases) may cause megaloblastic anemia, in addition to CNS dysfunction [3, 5, 6]. 

Hereditary folate malabsorption and deficiency of transcobalamin II respond to intramuscular treatment with folinic acid and vitamin Bj2, respectively [3]. 

Hereditary folate malabsorption Intestine choroid plexus 229050... 

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