Guidelines for the diagnosis and treatment of cobalamin and folate disorders

Devalia, Vinod; Hamilton, M. S.; Molloy, Anne M.

doi:10.1111/bjh.12959

Cited by 381 publications

(463 citation statements)

References 136 publications

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“…Most Black people in the townships nearby our hospital consume locally grown green vegetables (such as spinach) thus folate deficiency is rare in this population. Moreover, due to the recent evidence that the red blood cell folate levels do not offer better discrimination in folate deficiency than the serum folate does [21]. This qualitative data suggests that the participants in this group are not likely to have B12 and folate deficient from their dietary history.…”

Section: Discussionmentioning

confidence: 88%

Methyl Tetra Hydro Folate Reductase Enzyme Polymorphism in the Mothers with Previous Autosomal Aneuploidy Birth in the Indigenous African Population of Northern Region of South Africa

Duma¹,

Khine²

2017

J Down Syndr Chr Abnorm

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IntroductionAneuploidy is a genetic disorder where the total number of chromosomes is either less or more than the normal diploid number of 46, XX or 46, XY [1]. The most common aneuploidies in South Africa caused by autosomal chromosomal abnormalities include Down syndrome (Trisomy 21), Edward syndrome (Trisomy 18) and Patau syndrome (Trisomy 13). Globally the incidence for Down syndrome is about 1 in 650 to 1000 live births [2], Edward syndrome is 1 in 6000 live birth [3], and Patau is between 1 in 5000 to 29000 live birth [4]. Currently the prevalence rate is 1 out of 500 live birth for Down syndrome in South Africa with 1886 new cases diagnosed every year [5] and for Edward syndrome the prevalence is 1 in 4000 live birth and Patau is 1 in 8889 live birth [6,7]. The aetiology of these autosomal aneuploidies are believed to be due to non-disjunction of chromosome in maternal ovum during meiosis which is thought to be a sporadic, incidental event usually associated with older age group mothers. Notably, there is an increased incidence of aneuploidy babies has been observed in younger age group mothers with less than 35 years of age in South African black population [8].There were studies done in the Middle East families with recurrence aneuploidy births to determine if there is a genetic link. Krishna Murthy and Farag reported two unrelated Kuwaiti families each having 3 siblings with trisomy 21 as a result the researchers suggested that some genetic predisposition and gonadal mosaicism could be the underlying cause of recurrent aneuploidy in the younger mothers, thus increasing the risk of recurrence of such pregnancies [9]. There were studies that found that a particular polymorphism of one of these genes Methylenetetrahydrofolate reductase (MTHFR) might be a maternal risk factor for having child with Aneuploidy or Down syndrome and that a significant increase in plasma homocysteine levels exists in mothers of the children with Aneuploidy or Down syndrome [10,11].Increased homocysteine may result from dietary deficiency of folate and or vitamin B12 or from genetic polymorphism of Methylenetetrahydrofolate reductase (MTHFR). These genes encode the enzymes involved in the transfer of methyl group from sulpha containing amino acids (homocysteine and cysteine). Decreased transfer results in decrease methylation of DNA around the centromere region of chromosome 21, 18 and 13 proposed to be leading to aneuploidy. This hypothesis has led many researchers to further explore the evidence between DNA methylation of chromosome 21, 18, 13 in the unfertilized ovum but due to invasive nature of method involved in acquiring the pre-implementation studies, it has not been proven [10,[12][13][14][15][16].Indirect evidence of younger mothers having high level of plasma homocysteine with or without genetic polymorphisms would be the closest link to identifying the risk of recurrence aneuploidy in the AbstractBackground and purpose of the study: Aneuploidy births are highly prevalent in our population and some families, recurre...

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Section: Discussionmentioning

confidence: 88%

Methyl Tetra Hydro Folate Reductase Enzyme Polymorphism in the Mothers with Previous Autosomal Aneuploidy Birth in the Indigenous African Population of Northern Region of South Africa

Duma¹,

Khine²

2017

J Down Syndr Chr Abnorm

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“…13 As these results were not confirmed by metabolite testing, true rates of deficiency may thus be higher due to the low sensitivity and specificity of the assays used. 1,6,11 According to the British Committee for Standards in Haematology, the clinical assessment of the patient is still the most important aid to interpreting test results of vitamin B12 status as there is no 'gold standard' test to assess deficiency. 11 Haematological parameters are thought to be less useful in identifying such patients.…”

Section: Discussionmentioning

confidence: 99%

“…1,6,11 According to the British Committee for Standards in Haematology, the clinical assessment of the patient is still the most important aid to interpreting test results of vitamin B12 status as there is no 'gold standard' test to assess deficiency. 11 Haematological parameters are thought to be less useful in identifying such patients. In early deficiency, haemoglobin (Hb) and mean cell volumes (MCVs) may be normal.…”

Section: Discussionmentioning

confidence: 99%

Section: Investigationmentioning

confidence: 99%

“…11 These second line tests are not readily available and are limited to a few specialised laboratories. 1,11 Akin to international standards (11), serum B12 and folate levels are the first line of investigating deficiencies at Tygerberg Academic Hospital (TAH). 12 Local recommendations state that in populations where folate food fortification occurs, such as in South Africa, optimal assessment of vitamin status should include both serum and red blood cell (RBC) folate assays, as well as serum vitamin B12 measurement.…”

Section: Investigationmentioning

confidence: 99%

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Are we appropriately testing for vitamin B12 and folate deficiency?

Davids

Hoffmann

Naidoo

et al. 2018

Ann. Clin. Chem. & Lab. Med.

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BACKGROUNDThe most common reason for assessing vitamin B12 and folate status is a clinical suspicion of deficiency along with the haematological abnormality of macrocytic anaemia. However, there is often a lack of a precise clinical or haematological picture to guide the appropriate investigation of these patients. Normal haemoglobin or mean cell volumes are often found, masking the need for appropriate investigation. When abnormal haematological parameters are found, it is often a sign of advanced deficiency. In this study we investigated whether patients with haematological findings of macrocytosis and/or anaemia are appropriately investigated for vitamin B12 and folate deficiencies and whether clinicians request metabolite screening to assist with the diagnosis. METHODS This was a retrospective audit of data obtained from the laboratory information system for a six month period at a tertiary academic hospital. Adult patients with macrocytosis, anaemia or both were selected and laboratory records reviewed to determine whether they were investigated for vitamin B12 and folate deficiency. RESULTS Only 16.2% of patients with macrocytic anaemia, 7.8% of patients with isolated macrocytosis and 6.5% of patients with normocytic anaemia were tested for vitamin B12 and/or folate deficiency. Metabolite assays such as homocysteine and methylmalonic acid were not requested as part of a vitamin status assessment. CONCLUSION In our setting, vitamin B12 and folate assessment is a diagnostic dilemma, delaying identification of potentially debilitating disease. Clinicians need to be informed about earlier investigation and of the availability of metabolite screening and their use in establishing early deficiency.

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Interpretation of Vitamin B₁₂Status After a Roux-en-Y Gastric Bypass

Murali¹,

Mshs

2019

JAMA

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A 37-year-old woman with a history of diabetes, hypertension, obstructive sleep apnea, depression, and Roux-en-Y gastric bypass (RYGB) 16 years prior presented to an ambulatory care clinic with fatigue, loss of appetite, and hair loss. She lost 50.8 kg from the time of the procedure to presentation, her body mass index at presentation was 23, and her preoperative comorbidities were in remission. She did not have any nausea, abdominal pain, or change in bowel habits, but her periods had been more irregular over the past 2 to 3 months and, when present, lasted for 7 to 10 days. She also noted a tingling sensation in her hands and feet. She was under some financial stress after recently losing her job, and reported drinking 2 to 6 beers within a 2-hour period on the weekends. She took a gummy multivitamin sporadically and self-reported a daily total calorie intake of less than 500 kcal and less than 20 g of protein. On physical examination, although she reported having paresthesias in her fingertips and toes, her neurological examination findings were nonfocal. She exhibited bilateral flattening of the temporalis muscle and thenar eminence. Her vital signs were normal, and serum tests were ordered (Table ). AnswerC. The patient has both iron and vitamin B 12 deficiencies.The patient has B 12 deficiency and concomitant iron deficiency anemia. From her history, this is likely secondary to nonadherence with postoperative vitamin supplementation recommendations.

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Guidelines for the diagnosis and treatment of cobalamin and folate disorders

Cited by 381 publications

References 136 publications

Methyl Tetra Hydro Folate Reductase Enzyme Polymorphism in the Mothers with Previous Autosomal Aneuploidy Birth in the Indigenous African Population of Northern Region of South Africa

Methyl Tetra Hydro Folate Reductase Enzyme Polymorphism in the Mothers with Previous Autosomal Aneuploidy Birth in the Indigenous African Population of Northern Region of South Africa

Are we appropriately testing for vitamin B12 and folate deficiency?

Interpretation of Vitamin B₁₂Status After a Roux-en-Y Gastric Bypass

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Guidelines for the diagnosis and treatment of cobalamin and folate disorders

Cited by 381 publications

References 136 publications

Methyl Tetra Hydro Folate Reductase Enzyme Polymorphism in the Mothers with Previous Autosomal Aneuploidy Birth in the Indigenous African Population of Northern Region of South Africa

Methyl Tetra Hydro Folate Reductase Enzyme Polymorphism in the Mothers with Previous Autosomal Aneuploidy Birth in the Indigenous African Population of Northern Region of South Africa

Are we appropriately testing for vitamin B12 and folate deficiency?

Interpretation of Vitamin B12Status After a Roux-en-Y Gastric Bypass

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Interpretation of Vitamin B₁₂Status After a Roux-en-Y Gastric Bypass