Abstract: The present disclosure provides a method of detecting the presence or amount of a UBE3A protein in a sample, such as a human sample, using mass spectrometry based techniques. The methods described herein are useful for diagnosing Angelman syndrome, as well as monitoring disease progression and treatment effectiveness.

Abstract: In one aspect, the invention provides a method for alleviating a symptom in a patient with amyotrophic lateral sclerosis, comprising administering an efficacious therapeutic that is efficacious to the patient, the efficacious therapeutic, when administered to the patient, resulting in a level of a neurofilament protein in a biological sample of the patient that is lower than a level of neurofilament protein in a patient with amyotrophic lateral sclerosis not administered the therapeutic. In some embodiments, the patient is currently being administered with or has formerly been administered with either a non-efficacious therapeutic or a therapeutic that is different than the efficacious therapeutic.