Introduction
- Congenital Myopathies: Group of inherited muscle disorders presenting with:
- Hypotonia and weakness from birth.
- Characteristic histological and/or electron microscopic changes in muscle tissue.
Clinical Features
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Common Features
- Generalized hypotonia: "Floppy infant syndrome."
- Weakness:
- Prominent facial weakness ± ptosis.
- Hypotonic ‘frog-leg’ posture.
- Respiratory muscle involvement: May require ventilatory support.
- Bulbar muscle weakness: Feeding and speech difficulties.
- Extraocular muscle involvement: May present later.
- Hyporeflexia: Depressed or absent reflexes.
- Intact sensation and normal intelligence.
- CK levels: Normal or mildly elevated.
- EMG: Normal or shows myopathic pattern.
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Differentiation from Other Disorders
- No histopathological evidence of muscular dystrophy.
- Differential diagnosis includes:
- Prader-Willi syndrome.
- Neurometabolic disorders.
- Non-neuromuscular causes of neonatal hypotonia.
Diagnostic Tools