There is provided a method for screening for or, diagnosis or prognosis of a
neurological disorder in a subject, for determining the stage or severity of such a
neurological disorder in a subject, for identifying a subject at risk of developing such a
neurological disorder, or for monitoring the effect of therapy administered to a subject having such a neurological disorder, said method comprising: (a) analyzing a
test sample of
body fluid or tissue from the subject said sample comprising at least one
Protein Isoform selected from one of the following
Protein Isoform Families: PIF-1 and PIF-2; and (b) comparing the abundance of said
Protein Isoform(s) in the
test sample with the abundance of said
Protein Isoform(s) in a
test sample from one or more persons free from neurological disorder, or with a previously determined
reference range for that
Protein Isoform in subjects free from neurological disorder, wherein a diagnosis of or a positive result in screening for or a prognosis of a more advanced condition of said neurological disorder is indicated by an increased abundance of said
Protein Isoform(s) in the test sample relative to the abundance of said Protein Isoform(s) in the test sample from one or more persons free from neurological disorder, or with the previously determined
reference range for that Protein Isoform in subjects free from neurological disorder.