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Test Code HCYSP Homocysteine, Total, Plasma

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

Method Description

Total homocysteine is measured by stable isotope dilution microflow liquid chromatography tandem mass spectrometry.(Unpublished Mayo method)

Report Available

3 to 5 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Method Name

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

Secondary ID

80379