dystrophies

Dystrophies are a group of disorders characterized by degeneration or abnormal development of tissue, often with progressive dysfunction. The term is used in multiple organ systems, most commonly to describe muscular dystrophies.

Muscular dystrophy is a collection of inherited conditions defined by progressive muscle weakness and loss of muscle mass. Most forms are due to gene mutations that disrupt proteins essential for muscle fiber stability or membrane integrity. Duchenne and Becker muscular dystrophy are among the best known forms, caused by mutations in the DMD gene encoding dystrophin; they are X-linked and typically begin in childhood, with early proximal weakness and calf pseudohypertrophy. Becker is milder and later onset. Other muscular dystrophies include limb-girdle muscular dystrophies, which affect proximal muscles of the hips and shoulders and may be autosomal dominant or recessive; distal myopathies affect muscles further from the center of the body, with diverse genetic causes.

Non-muscular dystrophies include retinal dystrophies such as retinitis pigmentosa and corneal dystrophies, which similarly reflect tissue degeneration due to genetic defects.

Diagnosis involves clinical assessment, elevated serum creatine kinase, electromyography, genetic testing, and sometimes muscle biopsy showing dystrophic changes.

Management is supportive and multidisciplinary, including physical and occupational therapy, orthotic devices, respiratory and cardiac care as needed, and genetic counseling. Disease course and prognosis vary greatly by subtype; some forms present in early childhood with reduced life expectancy, others progress slowly in adulthood. Treatments are expanding in targeted therapies for specific genes, but cure remains limited.

Dystrophies are considered rare diseases, with substantial genetic heterogeneity and ongoing research into gene-based therapies.