Phenotypic expression of a novel desmin gene mutation: hypertrophic cardiomyopathy followed by systemic myopathy

Area of Science:

• Cardiology
• Genetics
• Muscle Biology

Background:

• Hypertrophic cardiomyopathy (HCM) is a genetic heart condition often linked to sarcomeric protein gene mutations.
• Extra-sarcomeric cytoskeletal proteins, like desmin, are also implicated in cardiomyopathies.
• Desmin mutations can lead to desmin-related myopathies, affecting muscle function.

Purpose of the Study:

• To identify the genetic cause of hypertrophic cardiomyopathy and subsequent general myopathy in a patient.
• To characterize a novel mutation in the desmin gene and its inheritance pattern.

Main Methods:

• Genetic sequencing to identify mutations in the desmin gene.
• Clinical evaluation of the patient and family members to assess phenotype and inheritance.

Main Results:

• A novel homozygous missense mutation, Thr219Pro, was identified in the desmin gene (1B α-helix domain).
• The patient presented with severe hypertrophic cardiomyopathy preceding the onset of general myopathy.
• Heterozygous parents were asymptomatic, indicating recessive inheritance of the desmin mutation.

Conclusions:

• A novel homozygous desmin mutation (Thr219Pro) can cause a severe hypertrophic cardiomyopathy phenotype that precedes general myopathy.
• This finding expands the spectrum of desmin-related myopathies and highlights the role of desmin in cardiac and skeletal muscle integrity.