Clinical Phenotypes of Pediatric Myopathies 

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• Congenital and infantile hypotonia of neurologic origin

• Congenital myopathies

• Congenital (neonatal onset) onset muscular dystrophy

• Non-congenital onset (non-neonatal onset) muscular dystrophies

• Metabolic and mitochondrial myopathies

• Inflammatory myopathy

• Others

Congenital and infantile hypotonia of neurologic origin Head

• Spinal muscular atrophy I, II, and III

Congenital myopathies: Most of them have onset of hypotonia and demonstrable morphologic changes at the time of birth but some may have later onset. They are generally non-progressive although rapid progression may also occur. Some of them may improve with age (*). CPK is usually normal and EMG may be normal or may show mild, non-specific changes.  Head

• Myotonic dystrophy, congenital type

• Minimal change myopathy (non-specific congenital myopathies)

• Central core disease

• Multicore (minicore) myopathy

• Nemaline myopathy

• Congenital fiber-type disproportion myopathy

• Myotubular myoathy (centronuclear myopathy)

• Integrin-alpha-7/beta-1 deficiency muscular dystrophy

• Zebra-body myopathy

• Hyaline body myopathy

• Fingerprint body myopathy

• Reducing body myopathy

• Cytoplasmic body (spheroid body) myopathy

• Sarcotubular myopathy

• Trilaminar myopathy

• Specific type 1 hypertrophy

• Cylindrical spiral myopathy

• Uniform type 1 fibers myopathy

• X-linked vacuolar myopathy with excessive autophagic vacuoles myopathy  

• X-linked vacuolar myopathy with cardiomyopathy and mental retardation

• Mixed myopathy

Congenital (neonatal onset) onset muscular dystrophy: Infantile onset of hypotonia associated with muscular dystrophy. Head

• Congenital muscular dystrophy- Merosin deficient type

• Congenital muscular dystrophy- Merosin-positive type

• Congenital muscular dystrophy- others

• Fukuyama  congenital dystrophy

• Walker-Warberg syndrome

• Muscle-eye-brain disease of Santavuori

• Marinesco-Sjögren syndrome

• Ullrich congenital muscular dystrophy

Non-congenital onset (non-neonatal onset) muscular dystrophies: Childhood onset progressive muscle weakness, usually heredofamilial. Head

• Duchene muscular dystrophy

• Becker’s muscular dystrophy

• Emery-Dreifuss muscular dystrophy

• Facial-scapulo-humeral dystrophy (Landouzy-Déjerine) and facio-scapulo-humeral syndromes

• Limb-girdle muscular dystrophy

• Distal muscular dystrophies

• Ocular muscular dystrophy

Metabolic and mitochondrial myopathies: Symptoms may be intermittent, induced by muscular effort, or permanent. Head

• Glycogenoses

•       Type II (acid maltase deficiency)

• Type III

• Type IV

• Type V (McArdle disease)

• Phosphofurctokinase deficiency

• Phosphorylase B kinase deficiency

• Myoadenylate deaminase deficiency

• Disorders of lipid metabolism

• Carnitine deficiency

• Primary muscle carnitine dficiency

• Deficits in carnitine-palmitoyl transferase

• Mitochondrial myopathies

• Myoglobinuria

Inflammatory myopathy: Myalgia is common; inflammatory cell infiltrate as a frequent pathologic component. Head

• Dermatomyositis

• Polymyositis of infants

• Benign acute childhood myositis (BACM) (myalgia cruris epidemica)

Others Head

• Post-infectious rhabodmyolysis