Over 80% of patient with myasthenia gravis (MG) will have acetylcholine receptor antibodies 
– next most common Ab associated with MG is the anti-muscle-specific receptor tyrosine kinase (MuSK)

Approximately 50% of double-negative (ie. MuSK and AChR negative) MG patients will have positive anti-LRP4 Ab 
– LRP4 is involved in MuSK activation