AGRN-, LRP4-, MUSK-Related CMS: Clinical, Neurophysiological, Morphological, Genetic and Pathological Mechanisms

Area of Science:

• Neuromuscular Biology
• Genetic Disorders
• Synaptic Function

Background:

• Congenital myasthenic syndromes (CMS) are inherited neuromuscular junction disorders.
• Mutations in over 35 genes cause CMS, affecting neuromuscular transmission.
• AGRN, LRP4, and MUSK gene mutations cause specific CMS subtypes with distinct mechanisms.

Purpose of the Study:

• To provide a comprehensive review of AGRN, LRP4, and MUSK-related CMS.
• To integrate clinical, genetic, and mechanistic data.
• To highlight diagnostic strategies and emerging therapeutic concepts.

Main Methods:

• Review of existing literature and patient data.
• Analysis of genetic variants and their functional consequences.
• Integration of findings from experimental models.

Main Results:

• AGRN, LRP4, and MUSK mutations impair agrin/LRP4/MuSK signaling, affecting NMJ formation and stability.
• Clinical presentations vary widely, with some subtypes unresponsive to standard treatments.
• Adrenergic agonists show potential benefit in specific cases.

Conclusions:

• AGRN, LRP4, and MUSK-related CMS offer insights into NMJ biology and synaptic regulation.
• Genotype-phenotype correlations are challenging due to inter-individual variability.
• Advances in sequencing and functional studies improve diagnosis and pave the way for personalized, mechanism-based treatments.