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Myotonic Dystrophy 1 (DMPK) Genetic Testing (Repeat Expansion)

Myotonic Dystrophy 1 (DMPK) Genetic Testing (Repeat Expansion)
TEST: MOL299
Test number copied
620084
MOL299
CPT: 81234
81234
Updated on 09/23/2020
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Genes Assessed


Specimen Requirements


Specimen

Blood | Extracted DNA | Cultured Fibroblasts | Muscle | Buccal Cells
Blood | Extracted DNA | Cultured Fibroblasts | Muscle | Buccal Cells

Volume

4 mL, 1 swab, or 200 ng of DNA, 75 mg muscle, 90% cell confluency
4 mL, 1 swab, or 200 ng of DNA, 75 mg muscle, 90% cell confluency

Container

Blood: Lavender-Top (EDTA) Tube, Buccal Swab from MNG Kit, Tissue or Extracted DNA: Sterile screw capped vial, Cultured cells: T25 flask
Blood: Lavender-Top (EDTA) Tube, Buccal Swab from MNG Kit, Tissue or Extracted DNA: Sterile screw capped vial, Cultured cells: T25 flask

Collection

Blood: Specimens should be shipped overnight in a secure container at room temperature. Extracted DNA: Should be shipped overnight at room temperature. If previously frozen, DNA can be shipped in an insulated container with wet or dry ice. Cultured Fibroblasts: T-25 flasks containing fibroblasts should be shipped in an insulated container at room temperature. Flasks should be completely filled with media and cells should be ~90% confluent. Fibroblast samples must be certified free from Mycoplasma. MNG is able to perform this service for a small charge (TC05). For NGS panels, TAT will be extended by 7-14 days if cells are not confluent upon arrival. Muscle: Samples should be shipped frozen in an insulated container with 5-7 lbs. dry ice, overnight. Buccal cells: Should be shipped overnight in a secure container at room temperature.
Blood: Specimens should be shipped overnight in a secure container at room temperature. Extracted DNA: Should be shipped overnight at room temperature. If previously frozen, DNA can be shipped in an insulated container with wet or dry ice. Cultured Fibroblasts: T-25 flasks containing fibroblasts should be shipped in an insulated container at room temperature. Flasks should be completely filled with media and cells should be ~90% confluent. Fibroblast samples must be certified free from Mycoplasma. MNG is able to perform this service for a small charge (TC05). For NGS panels, TAT will be extended by 7-14 days if cells are not confluent upon arrival. Muscle: Samples should be shipped frozen in an insulated container with 5-7 lbs. dry ice, overnight. Buccal cells: Should be shipped overnight in a secure container at room temperature.

Storage Instructions

Blood - ship ASAP, but stable up to 5 days post-collection at room temperature. DO NOT FREEZE; Swab - 60 day post-collection room temperature stability; DNA - ship at room temperature after extraction; Fibroblasts - ship flask in insulated container at room temp or refigerated; Muscle - ship in insulated container with 5-7 lbs of dry ice
Blood - ship ASAP, but stable up to 5 days post-collection at room temperature. DO NOT FREEZE; Swab - 60 day post-collection room temperature stability; DNA - ship at room temperature after extraction; Fibroblasts - ship flask in insulated container at room temp or refigerated; Muscle - ship in insulated container with 5-7 lbs of dry ice

Stability Requirements

Room Temperature: Blood - 5 days, Swab - 60 days, DNA - 30 days, Muscle - 0 days, Fibroblasts - 2-3 days; Refrigerated: Blood - 5 days, Swab - 60 days, DNA - 30 days, Muscle - 0 days, Fibroblasts - 2-3 days; Frozen: Blood - DO NOT FREEZE, Swab - 60 days, DNA - Indefinitely, Muscle - Indefinitely, Fibroblasts - Indefinitely; Freeze/Thaw: None
Room Temperature: Blood - 5 days, Swab - 60 days, DNA - 30 days, Muscle - 0 days, Fibroblasts - 2-3 days; Refrigerated: Blood - 5 days, Swab - 60 days, DNA - 30 days, Muscle - 0 days, Fibroblasts - 2-3 days; Frozen: Blood - DO NOT FREEZE, Swab - 60 days, DNA - Indefinitely, Muscle - Indefinitely, Fibroblasts - Indefinitely; Freeze/Thaw: None

Causes for Rejection

Extracted DNA A260:A280 ratio of outside of 1.8-2.0 range; Frozen blood EDTA tube; Thawed and/or fatty muscle sample; Insufficient buccal cell collection
Extracted DNA A260:A280 ratio of outside of 1.8-2.0 range; Frozen blood EDTA tube; Thawed and/or fatty muscle sample; Insufficient buccal cell collection

Test Details


Use

Type 1 myotonic dystrophy results from a mutation in the DMPK gene known as a trinucleotide repeat expansion. This mutation increases the size of the repeated CTG segment in the DMPK gene. People with type 1 myotonic dystrophy have from 50 to 5,000 CTG repeats in most cells. The number of repeats may be even greater in certain types of cells, such as muscle cells.
Type 1 myotonic dystrophy results from a mutation in the DMPK gene known as a trinucleotide repeat expansion. This mutation increases the size of the repeated CTG segment in the DMPK gene. People with type 1 myotonic dystrophy have from 50 to 5,000 CTG repeats in most cells. The number of repeats may be even greater in certain types of cells, such as muscle cells.

Limitations

Maximum reportable sizing: 150 repeats.
Maximum reportable sizing: 150 repeats.

Methodology

Repeat-Primed PCR (QP-PCR)
Repeat-Primed PCR (QP-PCR)

Recommended MNG Kits

SINGLE Blood Genetic Testing, Buccal Swab Genetic Testing
SINGLE Blood Genetic Testing, Buccal Swab Genetic Testing

Z-Code

ZB9AB
ZB9AB

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
620084 DMPK Repeat Expansion 21757-0 230163 Specimen Status N/A
620084 DMPK Repeat Expansion 21757-0 620085 DMPK RE Result 21757-0
620084 DMPK Repeat Expansion 21757-0 620086 DMPK RE Interpretation N/A