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Test Code HYCSP Homocysteine, Total, Plasma

Important Note

  • Must be drawn at Outpatient Lab at the Main Campus
  • Patient must be fasting
  • Collect in Lavender Tube
  • SEND ON ICE

Additional Codes

Mayo Test ID
HCYSP

Reporting Name

Homocysteine, Total, P

Useful For

An aid for screening patients suspected of having an inherited disorder of methionine metabolism including:

-Cystathionine beta-synthase deficiency (homocystinuria)

-Methylenetetrahydrofolate reductase deficiency and its thermolabile variants

-Methionine synthase deficiency

-Cobalamin (Cbl) metabolism

-Combined methyl-Cbl and adenosyl-Cbl deficiencies: Cbl C2, Cbl D2, and Cbl F3 deficiencies

-Methyl-Cbl specific deficiencies: Cbl D-Var1, Cbl E, and Cbl G deficiencies

-Transcobalamin II deficiency

-Adenosylhomocysteinase deficiency

-Glycine N-methyltransferase deficiency

-Methionine adenosyltransferase I/III deficiency

 

Screening and monitoring patients suspected of, or confirmed with, an inherited disorder of methionine metabolism

 

Evaluating individuals with suspected deficiency of vitamin B12 or folate

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Plasma EDTA


Necessary Information


1. Patient's age and sex are required.

2. Biochemical Genetics Patient Information (T602) is recommended, but not required, for suspected cases of inherited disorders of methionine metabolism.



Specimen Required


Collection Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: Green top (sodium or lithium heparin)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Immediately place specimen on wet ice.

2. Centrifuge and aliquot plasma into plastic vial within 4 hours of collection.

3. If blood cannot be placed on wet ice immediately, centrifuge and aliquot plasma into plastic vial within 1 hour of collection.

4. A refrigerated centrifuge is not required if the above time restrictions are met.


Specimen Minimum Volume

0.3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma EDTA Refrigerated (preferred) 28 days
  Frozen  309 days
  Ambient  28 days

Reference Values

Age

Total homocysteine (nmol/mL)

Female

Male

0-11 months

3.1-8.3

3.2-9.7

12-23 months

3.2-8.3

3.3-9.6

24-35 months

3.2-8.2

3.3-9.6

3 years

3.2-8.2

3.3-9.6

4 years

3.3-8.2

3.4-9.5

5 years

3.4-8.1

3.5-9.4

6 years

3.5-8.1

3.6-9.4

7 years

3.5-8.1

3.7-9.4

8 years

3.6-8.2

3.8-9.3

9 years

3.7-8.2

3.9-9.4

10 years

3.8-8.3

4.1-9.4

11 years

3.9-8.4

4.3-9.4

12 years

3.9-8.6

4.4-9.5

13 years

4.0-8.7

4.6-9.6

14 years

4.1-8.8

4.8-9.7

15 years

4.2-8.9

5.0-9.8

16 years

4.2-9.1

5.2-9.9

17 years

4.3-9.2

5.4-10.0

18 years

4.3-9.3

5.6-10.1

19 years

4.4-9.5

5.7-10.3

20 years

4.4-9.6

5.9-10.5

21 years

4.4-9.8

6.0-10.6

22 years

4.4-9.9

6.1-10.8

23 years

4.4-10.1

6.2-11.0

24 years

4.4-10.3

6.2-11.1

25 years

4.4-10.4

6.3-11.3

26 years

4.4-10.6

6.3-11.4

27 years

4.3-10.8

6.4-11.6

28 years

4.3-11.0

6.4-11.7

29 years

4.3-11.2

6.4-11.8

30 years

4.3-11.4

6.4-11.9

31 years

4.4-11.6

6.4-12.1

32 years

4.4-11.8

6.4-12.2

33 years

4.4-11.9

6.4-12.3

34 years

4.5-12.1

6.4-12.4

35 years

4.5-12.2

6.4-12.6

36 years

4.6-12.4

6.4-12.8

37 years

4.6-12.5

6.4-12.9

38 years

4.7-12.7

6.4-13.1

39 years

4.7-12.8

6.4-13.2

40 years

4.8-13.0

6.5-13.4

41 years

4.8-13.2

6.5-13.5

42 years

4.8-13.4

6.5-13.7

43 years

4.9-13.5

6.6-13.9

44 years

4.9-13.7

6.6-14.0

45 years

4.9-13.9

6.6-14.2

46 years

4.9-14.0

6.7-14.4

47 years

4.9-14.2

6.7-14.5

48 years

5.0-14.3

6.8-14.7

49 years

5.0-14.4

6.8-14.9

50 years

5.0-14.5

6.8-15.0

51 years

5.1-14.6

6.8-15.2

52 years

5.1-14.7

6.9-15.4

53 years

5.1-14.8

6.9-15.5

54 years

5.2-14.9

6.9-15.6

55 years

5.2-15.0

6.9-15.7

56 years

5.3-15.0

6.9-15.8

57 years

5.3-15.1

6.9-15.9

58 years

5.3-15.2

6.9-16.0

59 years

5.4-15.2

6.9-16.0

60 years

5.4-15.3

6.9-16.1

61 years

5.4-15.4

7.0-16.2

62 years

5.5-15.4

7.0-16.2

63 years

5.5-15.5

7.0-16.3

64 years

5.6-15.5

7.1-16.3

65 years

5.6-15.6

7.1-16.3

66 years

5.7-15.6

7.1-16.3

67 years

5.7-15.7

7.2-16.3

68 years

5.8-15.7

7.2-16.3

69 years

5.9-15.7

7.2-16.3

70 years

6.0-15.8

7.3-16.3

71 years

6.1-15.8

7.3-16.3

72 years

6.2-15.8

7.3-16.3

73 years

6.3-15.9

7.3-16.3

74 years

6.4-15.9

7.3-16.3

75 years

6.5-15.9

7.3-16.3

76 years

6.6-15.9

7.3-16.3

77 years

6.7-16.0

7.4-16.3

78 years

6.8-16.0

7.4-16.3

79 years

6.9-16.0

7.5-16.3

80 years

7.0-16.0

7.5-16.3

81 years

7.1-16.0

7.7-16.2

82 years

7.2-16.0

7.8-16.2

83 years

7.2-16.0

7.9-16.2

84 years

7.3-16.0

8.0-16.2

85 years

7.3-16.0

8.2-16.2

>85 years

7.4-16.0

8.3-16.2

Day(s) Performed

Monday through Friday

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83090

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HCYSP Homocysteine, Total, P 13965-9

 

Result ID Test Result Name Result LOINC Value
80379 Homocysteine, Total, P 13965-9

Interpretation

Elevated homocysteine concentrations are considered informative in patients evaluated for suspected nutritional deficiencies (vitamin B12, folate) and inborn errors of metabolism. Measurement of methylmalonic acid (MMA) distinguishes between vitamin B12 (cobalamin) and folate deficiencies, as MMA is only elevated in vitamin B12 deficiency. Treatment response can be evaluated by monitoring plasma homocysteine concentrations over time.

Clinical Reference

1. Mudd SH, Levy HL, Kraus JP: Disorders of transsulfuration. In: Valle D, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill, 2019. Accessed December 8, 2022. Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225084718&bookid=2709

2. Chrysant SG, Chrysant GS: The current status of homocysteine as a risk factor for cardiovascular disease: a mini review. Expert Rev Cardiovasc Ther. 2018 Aug;16(8):559–565. doi: 10.1080/14779072.2018.1497974

3. Refsum H, Smith AD, Ueland PM, et al: Facts and recommendations about total homocysteine determinations: an expert opinion. Clin Chem. 2004 Jan;50(1):3-32

4. Turgeon CT, Magera MJ, Cuthbert CD, et al: Determination of total homocysteine, methylmalonic acid, and 2-methylcitric acid in dried blood spots by tandem mass spectrometry. Clin Chem. 2010 Nov;56(11):1686-1695

5. Sacharow SJ, Picker JD, Levy HL: Homocystinuria caused by cystathionine beta-synthase deficiency. In: Adam MP, Everman DB, Mirzaa GM, et al, eds. GeneReviews [Internet] University of Washington, Seattle. 2004. Updated May 18, 2017. Accessed December 8, 2022. Available at www.ncbi.nlm.nih.gov/books/NBK1524/

Report Available

3 to 5 days

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)