Regulation of Blood Pyridoxal Phosphate in Riboflavin Deficiency in Man

Lakshmi, A.V.; Bamji, Mahtab S.

doi:10.1159/000175704

Cited by 28 publications

(4 citation statements)

References 5 publications

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“…Pyridoxamine 5′‐phosphate oxidase (PNPO in Figure S2a) is an FMN‐dependent enzyme that plays a role in the metabolism of vitamin B6 and synthesis of the coenzyme pyridoxal phosphate (PLP) (Clements & Anderson, 1980). Previous studies have demonstrated impaired synthesis of PLP in riboflavin deficiency (Lakshmi & Bamji, 1976; Mushtaq, Su, Hill, & Powers, 2009). This mechanism could explain the current metabolomics findings of reduced levels of B6 related compounds (pyridoxal and pyridoxate) and their restoration with riboflavin supplementation leading to activation of vitamin B6 metabolism.…”

Section: Discussionmentioning

confidence: 92%

Hematologic presentation and the role of untargeted metabolomics analysis in monitoring treatment for riboflavin transporter deficiency

Pillai

Amin

Gijavanekar

et al. 2020

American J of Med Genetics Pt A

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Riboflavin transporter deficiency (RTD) (MIM #614707) is a neurogenetic disorder with its most common manifestations including sensorineural hearing loss, peripheral neuropathy, respiratory insufficiency, and bulbar palsy. Here, we present a 2-year-old boy whose initial presentation was severe macrocytic anemia necessitating multiple blood transfusions and intermittent neutropenia; he subsequently developed ataxia and dysarthria. Trio-exome sequencing detected compound heterozygous variants in SLC52A2 that were classified as pathogenic and a variant of uncertain significance. Bone marrow evaluation demonstrated megaloblastic changes. Notably, his anemia and neutropenia resolved after treatment with oral riboflavin, thus expanding the clinical phenotype of this disorder. We reiterate the importance of starting riboflavin supplementation in a young child who presents with macrocytic anemia and neurological features while awaiting biochemical and genetic work up. We detected multiple biochemical abnormalities with the help of untargeted metabolomics analysis associated with abnormal flavin adenine nucleotide function which normalized after treatment, emphasizing the reversible pathomechanisms involved in this disorder. The utility of untargeted metabolomics analysis to monitor the effects of riboflavin supplementation in RTD has not been previously reported.

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Section: Discussionmentioning

confidence: 92%

Hematologic presentation and the role of untargeted metabolomics analysis in monitoring treatment for riboflavin transporter deficiency

Pillai

Amin

Gijavanekar

et al. 2020

American J of Med Genetics Pt A

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“…It is known that the activities o f flavin mononucleotide dependent pyridoxamine phosphate oxidase forming pyridoxal 5-phosphate and FAD-dependent oxidase in tissues decrease in riboflavin-deficient rats and hu man subjects [21]. In our laboratory, we have demonstrated that the daily urinary' excretion o f 4-pyridoxic acid (the ultimate product of vitamin B6 metabolism) significantly de creases in rats which received a riboflavindeficient diet despite a sufficient intake o f vitamin B() (8.13 ± 0.54 vs. 4.02 ± 0.85 pg).…”

Section: Discussionmentioning

confidence: 99%

Fluorometric Riboflavin Titration in Plasma by Ribof lavin<sub>-</sub>Binding Apoprotein as a Method for Vitamin B<sub>2</sub> Status Assessment

Коденцова

Vrzhesinskaya²,

Спиричев³

1995

Ann Nutr Metab

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A method for plasma riboflavin determination by riboflavin-binding apoprotein titration has been proposed for vitamin B₂ status evaluation. The method is based on the formation of riboflavin-apoprotein complex accompanied by full loss of fluorescence peculiar to free riboflavin. The data obtained have demonstrated a correlation with indicators of the vitamin B₂ status such as urinary excretion, erythrocyte content, and stimulation of the glutathione reductase activity by flavin adenine dinucleotide. Levels > 6 ng/ml blood plasma may be considered to be a criterion for normal vitamin B₂ supply.

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“…46 The metabolism of vitamin B 6 is flavin dependent and impaired synthesis of PLP in the presence of a riboflavin deficiency has been demonstrated in studies on humans and animals. 47 McKinley et al 48 reported that low-dose vitamin B 6 supplementation effectively lowers Hcy in healthy elderly persons who are both folate and riboflavin replete.…”

Section: Vitamin B 6 Statusmentioning

confidence: 99%

“…25 Vitamin B 12 deficiencies are most commonly because of problems of malabsorption, e.g. alcoholism 47 or inadequate dietary intake, especially in individuals who follow a strict vegetarian diet since vitamin B 12 is found only in animal-source foods. 50 A reduced vitamin B 12 status prevents the proper functioning of the methylation cycle by directly reducing the activity of MS, one of the enzymes needed for the methylation cycle to turn.…”

Section: Vitamin B 12 Statusmentioning

confidence: 99%

Dietary strategies to treat hyperhomocysteinaemia based on the biochemistry of homocysteine: a review

Nienaber-Rousseau

2014

South African Journal of Clinical Nutrition

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Hyperhomocysteinaemia is implicated in various diseases, including cardiovascular disease and cancer. Several conditions influence the concentration of homocysteine (Hcy), including demographic, genetic and lifestyle factors. With regard to the latter, dietary components may be manipulated as Hcy can be remethylated to methionine by folate, or metabolised by other one-carbon nutrients, such as betaine and its precursor, choline. This metabolic interplay enables the nutritionist or dietitian to be able to lower Hcy concentrations cost-effectively by tailoring an individual's diet, or by food enrichment and fortification strategies. Evidence supports the safety and benefits of Hcy reduction by simple dietary intervention. B vitamins, and betaine and choline intake lower Hcy, whereas methionine and certain beverages (coffee, tea and alcohol) increase it. Therefore, dietary determinants of Hcy raise the prospect of a simple, inexpensive and safe means of treating and/or preventing diseases contingent on this sulphur-containing protein.

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Regulation of Blood Pyridoxal Phosphate in Riboflavin Deficiency in Man

Cited by 28 publications

References 5 publications

Hematologic presentation and the role of untargeted metabolomics analysis in monitoring treatment for riboflavin transporter deficiency

Hematologic presentation and the role of untargeted metabolomics analysis in monitoring treatment for riboflavin transporter deficiency

Fluorometric Riboflavin Titration in Plasma by Ribof lavin<sub>-</sub>Binding Apoprotein as a Method for Vitamin B<sub>2</sub> Status Assessment

Dietary strategies to treat hyperhomocysteinaemia based on the biochemistry of homocysteine: a review

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