Autosomal – dominant ZNM (DNM2)

What is DNM2 associated centronuclear myopathy?

DNM2-associated centronuclear myopathy is caused by a mutation in the dyanmin 2 gene. The clinical phenotype, i.e. the severity of the disease, varies depending on the location of the defect on the gene. This myopathy can occur at birth or in adulthood and is described as slowly progressive. Symptoms that may only appear in adulthood are fatigue, muscle pain (myalgia) and leg cramps. In most cases, the muscle weakness begins in the upper arms and thighs, in some cases also in the lower arms and lower legs. Some sufferers find abilities such as walking, running and climbing stairs increasingly difficult. Some lose the ability to walk altogether, although in the majority of cases this does not occur before the age of 60. Other possible symptoms include drooping eyelids (ptosis) and partial or complete immobility of the eyes (ophthalmoplegia).
In cases where the disease is apparent immediately after birth or in early childhood, the symptoms consist of generalized muscle weakness, which can also affect the facial muscles (ptosis and ophthalmoplegia as possible symptoms). This weakness also leads to a weak sucking reflex and difficulty swallowing, which can lead to feeding problems. Respiratory insufficiency may develop.