What is nemaline myopathy, which CJI Chandrachud revealed his daughters suffer from?

Nemaline myopathy is a rare disorder that primarily affects skeletal muscles, leading to muscle weakness in the body. CJI DY Chandrachud recently revealed that both his foster daughters suffer from it and the diagnostic test is "terribly painful". "After the older child underwent the test, all...she could say [was]- 'Don’t allow my sister to go through the test'," he said.