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HelpTest ID MHDZ Methylmalonic Aciduria and Homocystinuria, cblD Type, Full Gene Analysis, Varies
Useful For
Confirmation of diagnosis of disorders belonging to the cblD complementation group
Distinguishing between cblC, cblD, and cblF types when methylmalonic aciduria and homocystinuria are identified
Distinguishing between cblA, cblB, and cblD variant 2 when methylmalonic aciduria is identified
Distinguishing between cblD variant 1, cblE, and cblG when homocystinuria is identified
Carrier screening in cases where there is a family history of methylmalonic aciduria or homocystinuria, but disease-causing mutations have not been identified in an affected individual
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| CULFB | Fibroblast Culture for Genetic Test | Yes | No |
Testing Algorithm
If skin biopsy is received, fibroblast culture for genetic test will be added and charged separately.
Special Instructions
Method Name
Polymerase Chain Reaction (PCR) Followed by DNA Sequence Analysis
Reporting Name
MMADHC Gene, Full Gene AnalysisSpecimen Type
VariesShipping Instructions
Specimen preferred to arrive within 96 hours of draw.
Specimen Required
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.
Submit only 1 of the following specimens:
Preferred:
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA) or yellow top (ACD)
Acceptable: Any anticoagulant
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send specimen in original tube.
Specimen Stability Information: Ambient (preferred)/Refrigerated/Frozen
Specimen Type: Cultured fibroblasts
Container/Tube: T-75 or T-25 flask
Specimen Volume: 1 Full T-75 or 2 full T-25 flasks
Specimen Stability Information: Ambient (preferred)/Refrigerated <24 hours
Specimen Type: Skin biopsy
Container/Tube: Sterile container with any standard cell culture media (eg, minimal essential media, RPMI 1640). The solution should be supplemented with 1% penicillin and streptomycin. Tubes can be supplied upon request (Eagle's minimum essential medium with 1% penicillin and streptomycin [T115]).
Specimen Volume: 4-mm punch
Specimen Stability Information: Refrigerated (preferred)/Ambient
Specimen Type: Blood spot
Supplies: Card - Blood Spot Collection (Filter Paper) (T493)
Container/Tube:
Preferred: Collection card (Whatman Protein Saver 903 Paper)
Acceptable: Ahlstrom 226 filter paper, or Blood Spot Collection Card (T493)
Specimen Volume: 2 to 5 Blood Spots on collection card (Whatman Protein Saver 903 Paper; Ahlstrom 226 filter paper; or Blood Spot Collection Card, T493)
Collection Instructions:
1. An alternative blood collection option for a patient >1 year of age is finger stick.
2. Let blood dry on the filter paper at ambient temperature in a horizontal position for 3 hours.
3. Do not expose specimen to heat or direct sunlight.
4. Do not stack wet specimens.
5. Keep specimen dry
Specimen Stability Information: Ambient (preferred)/Refrigerated
Additional Information:
1. For collection instructions, see Blood Spot Collection Instructions in Special Instructions.
2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777) in Special Instructions.
3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800) in Special Instructions.
Specimen Minimum Volume
Blood: 1 mL
Blood Spots: 5 punches, 3-mm diameter
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | ||
Reference Values
An interpretive report will be provided.
Day(s) and Time(s) Performed
Performed weekly; Varies
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
81479-Unlisted molecular pathology procedure
Fibroblast Culture for Genetic Test
88233-Tissue culture, skin or solid tissue biopsy (if appropriate)
88240-Cryopreservation (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| MHDZ | MMADHC Gene, Full Gene Analysis | 94207-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 53992 | Result Summary | 50397-9 |
| 53993 | Result | 82939-0 |
| 53994 | Interpretation | 69047-9 |
| 53995 | Additional Information | 48767-8 |
| 53996 | Specimen | 31208-2 |
| 53997 | Source | 31208-2 |
| 53998 | Released By | 18771-6 |
NY State Approved
YesForms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Molecular Genetics: Biochemical Disorders Patient Information (T527) in Special Instructions
3. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen: