[Recent Advances in α-dystroglycanopathy]

Area of Science:

• Biochemistry
• Genetics
• Neurology

Background:

• Fukuyama-type congenital muscular dystrophy (FCMD), muscle-eye-brain disease (MEB), and Walker-Warburg syndrome (WWS) are linked by aberrant glycosylation of alpha-dystroglycan (α-DG).
• This common pathomechanism underlies a spectrum of muscular dystrophies, now collectively termed 'alpha-dystroglycanopathies'.
• α-DG's laminin-binding activity is crucial for tissue integrity and is impaired by defective glycosylation.

Purpose of the Study:

• To review the history of basic and clinical research on alpha-dystroglycanopathies.
• To refine and broaden the understanding of the clinical spectrum of these disorders.
• To present recent advancements, including novel disease mechanisms and therapeutic strategies.

Main Methods:

• Review of existing literature on genetic and glycobiological evidence.
• Analysis of genotype-phenotype correlations in alpha-dystroglycanopathies.
• Discussion of enzymatic pathways involved in α-DG glycosylation.

Main Results:

• Aberrant glycosylation of α-DG is a unifying feature across various muscular dystrophies.
• Specific O-mannosyl tetrasaccharides and phosphodiester-linked structures on α-DG are vital for laminin binding.
• Mutations in genes like POMT1/2, POMGnT1, fukutin, and LARGE disrupt these critical glycosylation steps.

Conclusions:

• The term 'alpha-dystroglycanopathy' effectively unifies diverse disorders with a shared molecular defect.
• The clinical spectrum of alpha-dystroglycanopathies is broader than previously recognized.
• Emerging research offers insights into novel disease mechanisms and potential therapies, such as antisense oligonucleotide treatment for FCMD.