Confirm suspected laminopathy caused by LMNA deletions/duplications including Emery-Dreifuss muscular dystrophy type 2, Limb-girdle muscular dystrophy 1B or dilated cardiomyopathy.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics of Laminopathies: Mutations in the lamin A/C (LMNA) gene cause a broad range of clinical diseases collectively termed laminopathies. Clinical findings are highly variable.
Emery-Dreifuss muscular dystrophy, type 2 (EDMD2): Joint contractures, progressive muscle weakness and wasting, and cardiac disease with conduction defects and arrhythmias.
Inheritance: Autosomal dominant or de novo.
Cause: Pathogenic LMNA gene mutations.
Clinical Sensitivity: Clinical sensitivity is dependent upon the specific LMNA-related disorder.
Methodology: Multiplex ligation-dependent probe amplification (MLPA) to detect large LMNA coding region deletions/duplications.
Analytical Sensitivity and Specificity of MLPA: 90 and 98 percent, respectively.
Limitations: Diagnostic errors can occur due to rare sequence variations. Single base pair substitutions, small deletions/duplications, regulatory region mutations and deep intronic mutations will not be detected. Deletion/duplication breakpoints will not be determined. Large deletions/duplications in exon 8 may not be detected. Mutations in genes other than LMNA will not be detected.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2004540||LMNA Deletion/Duplication Specimen|
|2004541||LMNA Deletion/Duplication Interpretation|
- Emery-Dreifuss Muscular Dystrophy Type 2
- LMNA deletion/duplcation assay