Toe walking

My girlfriend is having this health issue: when she was 15 started walking on her toes.She had no other problems(muscular problems with her neck,arms....nothing) When she turned 16-17 she could not run anymore, and climbing stairs became a little difficult.Last week we visit a neurologist and she did an electro miography.The doctor said that he observed something with the muscles.He doesent feel no other problems(weeknes...etc) in her hands, neck...etc she can pull 3-4 kg dumbbells, she can raise 6-7 kg .Her spine is slightly deformed because of her 6 year toe walking.In her family no other cases like this was reported.Next step the doctor said is a muscular biopsy.Can anyone tell me more...is this symptoms sign of a serios illness?

[sal185]

hi there is a wide range of conditions that can cause these symptoms but my guess is becker's muscular dystrophy.. but it's a genetic disease and you said she had no history of a similar case.. so i'm not pretty sure but it's the closest thing to your description..
My advice is not to worry about it now just pray it's nothing serious and wait for the biopsy... Take care of yourself and your girlfriend..