Ordering Recommendation

Prenatal test for known DMD gene deletions/duplications previously identified in a family member. A copy of the family member's test result documenting the known familial variant is required.

Mnemonic

DMD DD FE

Methodology

Multiplex Ligation-dependent Probe Amplification

Performed

Varies

Reported

Within 10 days

New York DOH Approval Status

Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.

Specimen Required

Patient Preparation
Collect

Cultured amniocytes or Cultured CVS
AND Maternal Whole Blood Specimen
: Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Cultured Amniocytes or Cultured CVS: Transfer cultured amniocytes or cultured CVS to two T-25 flasks at 80 percent confluence. (Min: one T-25 flask at 80% confluence). Backup cultures must be retained at the client's institution until testing is complete. If the client is unable to culture amniocytes or CVS, this can be arranged by contacting ARUP Client Services at (800) 522-2787. Please contact an ARUP genetic counselor at (800) 242-2787 ext. 2141 prior to test submission.
Maternal Whole Blood Specimen:
Transport 2 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Cultured Amniocytes or Cultured CVS: CRITICAL ROOM TEMPERATURE. Must be received within 48 hours of collection due to viability of cells.
Maternal Whole Blood Specimen:
Room temperature.

Unacceptable Conditions
Remarks

Please contact an ARUP genetic counselor at (800) 242-2787 ext. 2141 prior to sample submission. Patient History Form is available on the ARUP Web site or by contacting ARUP Client Services at (800) 522-2787.

Stability

Cultured Amniocytes or Cultured CVS: Room temperature: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Maternal Whole Blood Specimen
: Room temperature: 7 days; Refrigerated: 1 month; Frozen: Unacceptable

Reference Interval

By report

Interpretive Data

Background information for Duchenne/Becker Muscular Dystrophy (DMD) Deletion/Duplication, Fetal:
Characteristics
: Symptoms of Duchenne muscular dystrophy (DMD) usually begin before age 6 and include fatigue, learning difficulties, muscle weakness (beginning in legs and pelvis), progressive difficulty walking with wheelchair needed at approximately 12 years and breathing difficulties and heart disease by age 20 years. Symptoms of Becker muscular dystrophy (BMD) are similar to DMD but start later and progress at a slower rate. Dilated cardiomyopathy has been observed in nearly all affected males and many female carriers of DMD and BMD.
Incidence
:  DMD: 1 in 3,500 male births, BMD: 1 in 19,000 male births.
Inheritance
: X-linked; de novo mutations occur in one-third of cases.
Penetrance
: Males: 100 percent. Females: Varies with X-chromosome inactivation.
Cause
: Pathogenic DMD mutations.
Clinical Sensitivity:
DMD: 55-75 percent, BMD: 75-90 percent.
Methodology
: Multiplex ligation-dependent probe amplification (MLPA) to detect large exonic deletions/duplications.
Analytical Sensitivity and Specificity
: Greater than 99 percent.
Limitations
: DMD base pair substitutions, small deletions/duplications, deep intronic, and regulatory region mutations will not be detected. Breakpoints for large deletions/duplications will not be determined. Diagnostic errors can occur due to rare sequence variation.

For quality assurance purposes, ARUP Laboratories will confirm the above result at no charge following delivery. Order Confirmation of Fetal Testing and include a copy of the original fetal report (or the mother's name and date of birth) with the test submission. Please contact an ARUP genetic counselor at (800) 242-2787 extension 2141 prior to specimen submission.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Compliance Category

Laboratory Developed Test (LDT)

Note

Hotline History

N/A

CPT Codes

81161; 81265 Fetal Cell Contamination (FCC)

Components

Component Test Code* Component Chart Name LOINC
0050548 Maternal Contamination Study Fetal Spec 59266-7
0050612 Maternal Contam Study, Maternal Spec 31208-2
2011232 DMD DelDup Fetal Specimen
2011233 Duchenne/Becker DelDup Fetal Interp 21247-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • Dystrophinopathies
Duchenne/Becker Muscular Dystrophy (DMD) Deletion/Duplication, Fetal