Congenital myopathy with fiber type disproportion (CFTD) is one of the rare forms of neuromuscular disease that are present at birth. The most common medical problems associated with CFTD are scattered muscular weakness, low muscle tone, and bone deformities. Other medical issues may include absent or low tendon reflexes and life threatening respiratory problems. Diagnosis is made by a muscle biopsy. Muscle biopsies of patients with CFTD show a disproportion in the size of type I and type II fibers. In muscle biopsies with CFTD, type I fibers are smaller than type II fibers. Other associated muscle biopsy findings are fiber I predominance and absence of type IIB fibers.

Genetics
The specific genetic changes responsible for causing CFTD are not known. This condition often occurs in patients who have no prior family history of the disorder. In other occasions, there may be several affected family members. When more than one family member is diagnosed with CFTD, the condition is probably inherited. In these cases, CFTD can be inherited in an autosomal dominant or an autosomal recessive mode of inheritance.

Since the genetics of CFTD have not been unraveled yet, our laboratory is interested in studying DNA and muscle biopsy samples of these patients since it would provide insight into the genetic cause of their muscular condition. Identification of the genes involved in CFTD could have direct clinical benefit to patients and their families by allowing for specific diagnostic testing such as carrier detection and prenatal diagnosis for those who wish. Furthermore, understanding the genetic cause(s) of congenital myopathies will increase our understanding of muscle biology and provide insights into future development of specific treatments and therapies.

Research
One of the goals of the research done at the Beggs laboratory is to determine which genes and proteins are involved in the cause of CFTD. We hope that what we learn will be useful for improving diagnosis and treatment of this condition. If you are the parent of a child with a congenital myopathy, if you yourself are affected, or if you are the healthcare provider of someone with CFTD, you may be able to help us better understand CFTD and to determine the genetic changes associated with the condition.