PMID- 32199937
OWN - NLM
STAT- MEDLINE
DCOM- 20201222
LR  - 20201222
IS  - 1873-2933 (Electronic)
IS  - 0009-9120 (Linking)
VI  - 80
DP  - 2020 Jun
TI  - An unusually high plasma concentration of homocysteine resulting from a 
      combination of so-called "secondary" etiologies.
PG  - 52-55
LID - S0009-9120(20)30079-5 [pii]
LID - 10.1016/j.clinbiochem.2020.03.010 [doi]
AB  - The metabolism of homocysteine is complex and involves many enzymes as well as 
      vitamin-derived cofactors. Any dysregulation of this metabolism may lead to 
      hyperhomocysteinemia (HHCy) which is responsible for many clinical disorders 
      including thromboembolic events. HHCy may result from very different etiologies 
      and is generally classified into three groups according to homocysteine 
      concentrations: moderate (<30 micromol/L), intermediate (30-100 micromol/L) or major 
      (>100 mumol/L). Major HHCy cases are generally due to monogenic defects of key 
      enzymes involved in homocysteine metabolism, such as cystathionine-beta-synthase or 
      5,10-methylene-tetrahydrofolate reductase, or to any defect in vitamin B(12) 
      absorption, transport or metabolism. By contrast, moderate and intermediate HHCy 
      tend to result from so-called "secondary" etiologies (e.g. tobacco, drugs, 
      alcohol, vitamin deficiencies or pathological contexts). Here we describe the 
      case of a patient with an unusually high plasma homocysteine concentration 
      (1562 mumol/L) which was only explained by a combination of such secondary 
      etiologies, among them chronic renal failure, hypothyroidism, the homozygous 
      C677T MTHFR variant, a novel heterozygous variant of the MSR gene, and a vitamin 
      deficiency. In addition, this patient exhibited a spectacular decline in 
      homocysteine concentrations (returning to normal) after betaine and vitamin 
      administration. In conclusion, this case highlights that major HHCy may also 
      result from the combination of secondary etiologies, with vitamin deficiency as a 
      triggering factor.
CI  - Copyright (c) 2020 The Canadian Society of Clinical Chemists. Published by Elsevier 
      Inc. All rights reserved.
FAU - Jaisson, Stephane
AU  - Jaisson S
AD  - University Hospital of Reims, Biochemistry Department, Reims, France; University 
      of Reims Champagne-Ardenne, Faculty of Medicine, MEDyC Unit CNRS UMR n degrees 7369, 
      Reims, France. Electronic address: sjaisson@chu-reims.fr.
FAU - Desmons, Aurore
AU  - Desmons A
AD  - University Hospital of Reims, Biochemistry Department, Reims, France.
FAU - Braconnier, Antoine
AU  - Braconnier A
AD  - University Hospital of Reims, Nephrology Unit, Reims, France.
FAU - Wynckel, Alain
AU  - Wynckel A
AD  - University Hospital of Reims, Nephrology Unit, Reims, France.
FAU - Rieu, Philippe
AU  - Rieu P
AD  - University Hospital of Reims, Nephrology Unit, Reims, France.
FAU - Gillery, Philippe
AU  - Gillery P
AD  - University Hospital of Reims, Biochemistry Department, Reims, France; University 
      of Reims Champagne-Ardenne, Faculty of Medicine, MEDyC Unit CNRS UMR n degrees 7369, 
      Reims, France.
FAU - Garnotel, Roselyne
AU  - Garnotel R
AD  - University Hospital of Reims, Biochemistry Department, Reims, France.
LA  - eng
PT  - Case Reports
DEP - 20200319
PL  - United States
TA  - Clin Biochem
JT  - Clinical biochemistry
JID - 0133660
RN  - 0LVT1QZ0BA (Homocysteine)
RN  - 12001-76-2 (Vitamin B Complex)
RN  - 3SCV180C9W (Betaine)
RN  - EC 1.5.1.20 (MTHFR protein, human)
RN  - EC 1.5.1.20 (Methylenetetrahydrofolate Reductase (NADPH2))
RN  - P6YC3EG204 (Vitamin B 12)
RN  - Q573I9DVLP (Leucovorin)
RN  - Methylenetetrahydrofolate reductase deficiency
SB  - IM
MH  - Aged
MH  - Betaine/administration & dosage
MH  - Female
MH  - Homocysteine/*blood
MH  - Homocystinuria/blood/genetics
MH  - Humans
MH  - Hyperhomocysteinemia/blood/*etiology
MH  - Leucovorin/administration & dosage
MH  - Methylenetetrahydrofolate Reductase (NADPH2)/blood/deficiency/genetics
MH  - Muscle Spasticity/blood/genetics
MH  - Psychotic Disorders/blood/genetics
MH  - Vitamin B 12/administration & dosage
MH  - Vitamin B 12 Deficiency/*blood
MH  - Vitamin B Complex/administration & dosage
OTO - NOTNLM
OT  - Homocysteine
OT  - Major hyperhomocysteinemia
OT  - Vitamin deficiency
COIS- Declaration of Competing Interest The authors declare that they have no known 
      competing financial interests or personal relationships that could have appeared 
      to influence the work reported in this paper.
EDAT- 2020/03/23 06:00
MHDA- 2020/12/23 06:00
CRDT- 2020/03/23 06:00
PHST- 2020/01/20 00:00 [received]
PHST- 2020/03/16 00:00 [revised]
PHST- 2020/03/17 00:00 [accepted]
PHST- 2020/03/23 06:00 [pubmed]
PHST- 2020/12/23 06:00 [medline]
PHST- 2020/03/23 06:00 [entrez]
AID - S0009-9120(20)30079-5 [pii]
AID - 10.1016/j.clinbiochem.2020.03.010 [doi]
PST - ppublish
SO  - Clin Biochem. 2020 Jun;80:52-55. doi: 10.1016/j.clinbiochem.2020.03.010. Epub 
      2020 Mar 19.