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Test ID: MGRM    
Myasthenia Gravis (MG) Evaluation with MuSK Reflex, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Diagnosis for autoimmune myasthenia gravis (MG) in adults and children

 

Distinguishing autoimmune from congenital MG in adults and children

 

Establishing a quantitative baseline value that allows comparison with future levels if weakness is worsening

Highlights

Seropositivity confirms a clinical or electrophysiologic diagnosis of autoimmune myasthenia gravis (MG).

 

Second-line muscle-specific kinase (MuSK) antibody test positivity confirms a clinical or electrophysiologic diagnosis of autoimmune MG where first-line serological tests (acetylcholine receptor: AChR binding and modulating antibodies) are negative.

Profile Information A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.

Test IDReporting NameAvailable SeparatelyAlways Performed
MGRMIMG Interpretive CommentsNoYes
ARBIACh Receptor (Muscle) Binding AbYesYes
STRStriational (Striated Muscle) Ab, SYesYes
ARMOACh Receptor (Muscle) Modulating AbNoYes

Reflex Tests Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test IDReporting NameAvailable SeparatelyAlways Performed
MUSKMuSK Autoantibody, SYesNo
GD65SGAD65 Ab Assay, SYesNo
GANGAChR Ganglionic Neuronal Ab, SNoNo
VGKCNeuronal (V-G) K+ Channel Ab, SNoNo
CRMWSCRMP-5-IgG Western Blot, SYesNo

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

If acetylcholine receptor (AChR) modulating antibodies are > or =90% and striational antibodies are > or =1:120, then ganglionic AChR neuronal autoantibody, glutamic acid decarboxylase autoantibody, neuronal voltage-gated potassium channel autoantibody, and collapsin response-mediator protein-5 (CRMP-5)-IgG Western blot will be performed at an additional charge.

 

If AChR-binding antibodies are < or =0.02 and AChR-modulating antibodies are < or =20%, then muscle-specific kinase (MuSK) autoantibody will be performed at an additional charge.

 

See Myasthenia Gravis Evaluation with MuSK Reflex Algorithm in Special Instructions.

Special Instructions Library of PDFs including pertinent information and forms related to the test

Method Name A short description of the method used to perform the test

ARBI, ARMO, GANG, VGKC: Radioimmunoassay (RIA)

STR: Enzyme Immunoassay (EIA)

CRMWS: Western Blot

NY State Available Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name Lists a shorter or abbreviated version of the Published Name for a test

MG Evaluation with MuSK Reflex, S

Aliases Lists additional common names for a test, as an aid in searching

Acetylcholine Receptor (Muscle AChR) Antibodies
Ach Receptor Ab
AChR Receptor Blocking Ab
AChR (Acetylcholine Receptor)
Anti-Skeletal Muscle Antibodies
Binding, Blocking, and Modulating Abs
Blocking Ab
GAD65 (Glutamic Acid Decarboxylase)
Glutamate Decarboxylase Antibodies (GAD65)
Muscle End-Plate Antibodies
Myasthenia Gravis
Myasthenia Gravis Antibodies
MuSK myasthenia
Myoid Antibody
Neuronal Potassium Channel Ab
Potassium Channel Antibodies (specify)
Thymoma
VGKC
VGPC
Voltage-Gated Potassium Channel Ab
MUSK