|Dysferlin (DYSF) Gene Sequencing||
Analysis of the entire coding region: Sequence analysis
Polymerase chain reaction (PCR)
|Container Type||Container Size||Specimen Volume|
Purple tube (EDTA)
|4 mL||4 mL-8 mL|
Room temperature - 24 hour(s)
Refrigerated - 72 hour(s)
- Do not centrifuge
- Do not freeze
- Transport to laboratory as soon as possible
Reasons for Rejection
- Centrifuged specimen
- Frozen specimen
- Wrong collection tube
- Clotted specimen
- Delayed or improper handling
Please click on the Lab Form Link in the Forms Section to print and complete the Genetic Test Requisition Form. Submission of completed Genetic Test Requisition Form is required, and submission of informed consent form is recommended but not required. If available, please also include muscle biopsy results.
This test is a full gene sequencing analysis of the DYSF gene. Presence of a pathogenic variant (mutation) in both alleles of this gene causes limb-girdle muscular dystrophy (LGMD) type 2B, which is a dysferlinopathy type of LGMD and is inherited in autosomal recessive manner. LGMD is a diverse group of disorders affecting the voluntary muscles, mainly around the pelvic (hip) and shoulder regions. In LGMD, the onset of symptoms is in late childhood, adolescence or even adult life. Inheritance in LGMD can be autosomal dominant (LGMD type 1) or autosomal recessive (LGMD type 2). Sometimes it is difficult to separate the different forms of LGMD based on clinical symptoms alone. Age of onset, progression, and distribution of the weakness and wasting vary considerably among individuals and genetic subtypes. The limb-girdle muscular dystrophies typically show dystrophic changes on muscle biopsy, which is usually associated with elevated serum creatine kinase concentration. Biochemical testing (i.e., protein testing by immunostaining or immunoblotting) performed on a muscle biopsy can establish the diagnosis of the following LGMD types: sarcoglycanopathy, calpainopathy, dysferlinopathy, and dystroglycanopathy. In some cases, demonstration of complete or partial deficiencies for any particular protein can then be followed by mutation studies of the corresponding gene. It is important to note that in some cases, clinical symptoms and mode of inheritance may be more useful than muscle biopsy results.
Targeted DYSF mutation analysis is available for family members when familial mutation is known (see Test Code: FMLIS).