Scroll back to top

Comprehensive Muscular Dystrophy/Myopathy (NGS Panel and Copy Number Analysis + mtDNA)

CPT: 81460, 81465, 81479, 81161, 81405 x6, 81406 x2, 81408 x3

Genes Assessed


      Specimen Requirements


      Specimen

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


      Volume

      Blood: Draw blood in a lavender top EDTA tube, Sample Stability: 5-7 days, Preferred volume: 4 ml, Minimum volume: 2 ml, DO NOT FREEZE. Extracted DNA: From leukocytes, muscle, or fibroblasts: Preferred quantity: 1 microgram, Minimum quantity: 800 nanograms. Genomic DNA should be eluted in sterile Dnase/Rnase free water or TE. The A260:A280 ratio should be 1.8-2.0. Cultured Fibroblasts: Two T-25 flasks of fibroblasts, preferably ~90% confluent. TAT will be extended by 7-14 days if cells are not confluent upon arrival. Muscle: 50-75 milligrams muscle snap frozen in liquid nitrogen and maintained at -80┬░Celsius or below. Buccal Cells: One buccal swab should be used for collection. Do not discard solution in collection tube. Follow collection instructions supplied. Stability at ambient temperature is 60 days.


      Container

      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.


      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


      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


      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


      Test Details


      Use

      Congenital myopathies and congenital muscular dystrophies (CMDs) are a clinically and genetically heterogeneous group of disorders, characterized by hypotonia and poor reflexes at birth or in the first years of life. They were traditionally classified by clinical phenotypes, histopathology, and creatine kinase levels. Currently molecular diagnosis is used to distinguish the subtypes. Variable age of onset and disease severity is observed between the congenital myopathies and CMDs. The congenital myopathies are clinically defined by stable or slowly progressive muscle weakness and hypotonia that typically occurs within the first year after birth, that may be accompanied by delayed motor milestones and breathing difficulties. Variable underlying histologic features have been noted for the congenital myopathies, but histopathology is likely to include structural changes without the dystrophic features seen in muscular dystrophies. The CMDs are subdivided into categories by protein function or gene: merosin deficiency (LAMA2), Ullrich congenital muscular dystrophy (COL6A1/2/3), rigid spine syndrome (SEPN1), LMNA-related CMD, and alpha-dystroglycanopathy (FKTN, FKRP). The CMDs with normal intellectual development are often caused by genetic defects of the extracellular matrix proteins (LAMA2, COL6A1/2/3) or the endoplasmic reticulum (SEPN1). Most congenital muscular dystrophies are inherited in an autosomal recessive manner but some subtypes are inherited in an autosomal dominant manner. Congenital myopathies are inherited in autosomal recessive and autosomal dominant manners. Many of the genes involved encode proteins that are critical components of the extracellular matrix, nuclear envelope, or endoplasmic reticulum. Several others are involved in the processes of glycosylation or ubiquitin-mediated degradation. Current evaluation and distinction between these disorders relies primarily on molecular testing to identify a specific subtype that can further guide management and treatment.


      Methodology

      Next-Generation Sequencing


      Recommended MNG Kits

      SINGLE Blood Genetic Testing, Buccal Swab Genetic Testing


      Z-Code

      ZB5XY