Inclusion body myopathy 2 (IBM2) is an inherited disorder that is caused by lack of a bifunctional enzyme UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase. This disorder primarily affects skeletal muscles, which are necessary for body movement. Affected individuals begin to have muscle weakness in the lower legs in the late teens or early adult years. The weakness continues to deteriorate over time and eventually spreads to the hands, thighs, hips, and shoulders. Muscle weakness makes walking increasingly difficult, and affected people usually lose the ability to walk within 20 years after symptoms appear. Intellect is unaffected by IBM2 but effect on life expectancy is unknown. There is no cure for IBM2; however medical surveillance and care may help to improve some symptoms and overall condition of life. IBM2 is caused by pathogenic variants in the GNE gene.