Causes Congenital fibre type disproportion (CFTD)

Congenital fibre type disproportion (CFTD) is an inherited condition. In most instances, the myopathy is thought to be passed on in an autosomal recessive pattern, meaning that a child would have inherited one copy of the mutation from each parent, although neither of them usually has any symptoms

There have, however, been cases reported of autosomal dominant inheritance, where only one copy of the mutation has caused the condition. In such cases, all children of an affected parent have a 50 percent chance of inheriting the condition. For both patterns of inheritance, both males and females can be affected but there is also evidence that one form of CFTD may be more common in males than females. Many sporadic cases have also been seen, where there has been no previous family history.

CFTD has now been associated with mutations in several genes: the muscle α-actin (ACTA1) gene, the selenoprotein N (SEPN1) gene, the α-tropomyosin 3 (TPM3) gene, the skeletal muscle ryanodine receptor (RYR1) gene and the slow/β-cardiac myosin heavy chain (MYH7) gene. All of these genes have also been implicated in other congenital myopathies, again indicating a possible overlap between CFTD and these conditions.