Duchenne Muscular Dystrophy (DMD) |
Early childhood (2-5 years) |
Progressive muscle weakness, difficulty walking, Gowers' sign, scoliosis. |
Mutation in the DMD gene on the X chromosome, leading to dystrophin deficiency. |
X-linked recessive |
Physical therapy, corticosteroids (e.g., prednisone), supportive care, and potential gene therapy. |
Progressive loss of ambulation, life expectancy improved with care; many live into their 30s or 40s. |
Clinical evaluation, genetic testing, imaging studies, functional assessments, and cardiac monitoring. |
Becker Muscular Dystrophy (BMD) |
Adolescence or early adulthood |
Similar to DMD but less severe; muscle weakness primarily affects proximal muscles. |
Mutation in the DMD gene but with a partially functional dystrophin protein. |
X-linked recessive |
Physical therapy, corticosteroids, and management of cardiac symptoms. |
Slower progression than DMD; many maintain ambulation into their 30s or 40s. Life expectancy near normal. |
Clinical evaluation, genetic testing, imaging studies, functional assessments, and cardiac monitoring. |
Myotonic Dystrophy |
Adulthood (usually in the 20s or 30s) |
Muscle stiffness and weakness, myotonia (delayed muscle relaxation), cataracts, heart issues. |
Mutation in the DMPK gene (Type 1) or CNBP gene (Type 2), leading to expanded trinucleotide repeats. |
Autosomal dominant |
Symptomatic treatment for myotonia, physical therapy, and management of associated conditions. |
Prognosis varies; Type 1 often affects life expectancy, while Type 2 is milder. |
Clinical evaluation, genetic testing, imaging studies, and monitoring for associated conditions. |
Limb-Girdle Muscular Dystrophy (LGMD) |
Childhood to early adulthood |
Weakness in the shoulder and hip girdle muscles, difficulty with climbing stairs and lifting objects. |
Several genetic mutations depending on subtype (e.g., CALP1, DYSF, etc.). |
Autosomal recessive or autosomal dominant |
Physical therapy, occupational therapy, and management of specific symptoms. |
Prognosis varies by subtype; some forms are slowly progressive with relatively good outcomes. |
Clinical evaluation, genetic testing, imaging studies, and functional assessments. |
Facioscapulohumeral Muscular Dystrophy (FSHD) |
Adolescence or early adulthood |
Weakness in facial, shoulder, and upper arm muscles, winged scapula, and facial weakness. |
Deletion of repetitive DNA sequences in the DUX4 gene on chromosome 4. |
Autosomal dominant |
Physical therapy, occupational therapy, and support for functional impairment. |
Typically slow progression; many maintain independence but may experience mobility issues. |
Clinical evaluation, genetic testing, imaging studies, and functional assessments. |
Congenital Muscular Dystrophy (CMD) |
At birth or early infancy |
Severe muscle weakness from birth, joint contractures, developmental delays. |
Various genetic mutations (e.g., LAMA2, COL6A1). Often associated with structural muscle abnormalities. |
Autosomal recessive |
Physical therapy, orthopedic interventions, and supportive care tailored to individual needs. |
Prognosis varies widely; some achieve significant motor milestones, while others experience severe disability. |
Clinical evaluation, genetic testing, imaging studies, and developmental assessments. |