Congenital fibre type disproportion. A case report

Area of Science:

• Neurology
• Pediatrics
• Muscle Pathology

Background:

• Congenital myopathies are a group of inherited muscle diseases presenting at birth or early infancy.
• Fibre type disproportion (FTD) is a histological pattern characterized by an unequal distribution of slow-twitch (Type I) and fast-twitch (Type II) muscle fibers.
• This pattern can be associated with various congenital myopathies, including nemaline myopathy and central core disease.

Observation:

• A 14-year-old White female presented with a history of being a 'floppy baby' with significantly delayed developmental milestones.
• Clinical suspicion for congenital muscle dystrophy was raised due to the patient's persistent hypotonia and motor deficits.
• Diagnostic workup included a quadriceps muscle biopsy for detailed histological examination.

Findings:

• Muscle biopsy revealed the characteristic histological features of congenital fibre type disproportion.
• This finding confirmed the diagnosis of congenital myopathy with fibre type disproportion.
• The patient's clinical presentation correlated with the pathological findings.

Implications:

• This case highlights the importance of muscle biopsy in diagnosing congenital myopathies, even in older children presenting with long-standing symptoms.
• Understanding fibre type disproportion is crucial for accurate diagnosis and potential genetic counseling in affected families.
• Further research into the specific genetic underpinnings and long-term management strategies for congenital myopathy with FTD is warranted.