Clinical variability in congenital fiber type disproportion

Area of Science:

• Neurology
• Genetics
• Pediatrics

Background:

• Congenital Fiber Type Disproportion (CFTD) is recognized as a distinct clinicopathological entity.
• Typical CFTD involves congenital hypotonia, weakness, contractures, and skeletal abnormalities.

Observation:

• This study presents 5 cases, including siblings, meeting CFTD histological criteria.
• Clinical presentations varied significantly, deviating from the stereotyped syndrome.
• One case showed only mild hypotonia, while another had severe motor impairment and multiple anomalies.

Findings:

• CFTD exhibits a broader clinical and phenotypic variability than previously understood.
• Diagnosis based solely on clinical presentation is unreliable due to this variability.
• Muscle biopsy is essential for accurate CFTD diagnosis.

Implications:

• CFTD should be considered a congenital myopathy diagnosed via muscle biopsy.
• Relying on clinical characteristics alone can lead to misdiagnosis or delayed diagnosis.
• Further research into the genetic and molecular basis of CFTD variability is warranted.