Homocysteine (Hcy) is a sulfur-containing non-proteinogenic amino acid formed during the
metabolism of the essential amino acid methionine. Hcy is considered a risk factor for …

Most rare clinical missense variants cannot currently be classified as pathogenic or benign.
Deficiency in human 5, 10-methylenetetrahydrofolate reductase (MTHFR), the most common …

Genetic homocystinurias are a group of inborn errors of metabolism that result in the
massive excretion of homocysteine (Hcy) in the urine due to Hcy accumulation in the body …

S-adenosyl methionine, which is formed from methionine, is an essential methyl donor
within the central nervous system. Methionine is formed by the enzyme methionine synthase …

Two enzymes in the transsulfuration pathway of homocysteine—cystathionine beta-synthase
(CBS) and gamma-cystathionase (CTH)—use cysteine and/or homocysteine to produce the …

Imerslund-Gräsbeck syndrome (IGS) is a rare autosomal recessive disorder characterized
by vitamin B12 malabsorption. Most patients present with non-specific symptoms attributed …

Background and purpose Juvenile‐or adult‐onset forms of severe 5, 10‐
methylenetetrahydrofolate reductase (MTHFR) deficiency manifesting as complicated …

We report seven cases from our clinic with transcobalamin receptor deficiency (TCRD).
None of our cases have experienced health issues or metabolic decompensation. All have …

Background: Granulomatous mastitis (GM) is a rare chronic inflammatory disease of the
breast. The current therapeutic effects of the antibiotic therapy and surgical or …

Vitamin B12 (Cbl) is needed for just two metabolic reactions in man, the methylation of
homocysteine to methionine (cofactor methyl-Cbl) and the conversion of methylmalonyl-CoA …