Females with X-Linked Muscle Disorders: an underestimated patient population

Area of Science:

• Genetics
• Neurology
• Molecular Biology

Background:

• Traditionally, female carriers of X-linked disorders were considered asymptomatic due to gene compensation.
• Recent literature indicates symptomatic presentations in female carriers of X-linked diseases.
• X-chromosome inactivation (XCI) is a key mechanism potentially explaining these clinical manifestations.

Purpose of the Study:

• To review the relationship between skewed XCI and clinical symptoms in female carriers of X-linked muscle disorders.
• To focus on Duchenne muscular dystrophy, Becker muscular dystrophy, Emery-Dreifuss muscular dystrophy, and Myotubular Myopathy.
• To emphasize the need for guidelines for recognizing and treating affected females.

Main Methods:

• Literature review focusing on X-linked muscle disorders and XCI.
• Analysis of studies correlating XCI patterns with clinical phenotypes in female carriers.
• Synthesis of evidence linking skewed XCI to disease severity.

Main Results:

• A tendency exists for females with more severe phenotypes to exhibit skewed XCI patterns.
• Females with intermediate phenotypes often display random XCI patterns.
• Skewed XCI can lead to reduced protein expression, causing symptoms in carriers.

Conclusions:

• Skewed XCI is associated with more severe phenotypes in female carriers of X-linked muscle disorders.
• Clinical recognition of affected females is increasing, necessitating specific management guidelines.
• Availability of causal therapies underscores the need for proper diagnosis and access to treatment for women.