Patent ID: 7378231

Claim:
A method of diagnosing or monitoring a lysosomal storage disorder in a subject, comprising: obtaining a first sample from the subject; measuring a first level of at least a first saposin in the first sample obtained from the subject; comparing the first level to a baseline level, wherein the baseline level is the level of at least the first saposin as determined in a control population of subjects unaffected by the lysosomal storage disorder; and determining an absence, a presence or extent of a lysosomal storage disorder when the first level is similar or different than the 95 th percentile of the baseline level of at least the first saposins in the control population; wherein, (i) the similarity of the first level compared to the baseline level is an indicator of absence of the lysosomal storage disorder in the subject; (ii) the difference of the first level compared to the baseline level is an indicator of presence or extent of the lysosomal storage disorder in the subject; (iii) the first sample is a plasma, serum, or whole blood sample; and (iv) the first saposin comprises saposin A, and the lysosomal storage disorder is selected from the group consisting of Cystinosis, Fabry disease, Gaucher's disease, GM-I-gangliosidosis, I Cell disease, Krabbe disease, MPS I, MPS II, MPS IVA, MPS VI, Niemann-Pick (A/B), Niemann-Pick (C), Sandhoff's disease, Sialic Acid Storage disease, Tay-Sachs Type I and Wolman disease; or the first saposin comprises saposin B, and the lysosomal storage disorder is selected from the group consisting of Fabry disease, Gaucher's disease, Niemann-Pick (A/B), Pompe's disease, and Sandhoff's disease; or the first saposin comprises saposin C, and the lysosomal storage disorder is selected from the group consisting of Cystinosis, Fabry disease, Gaucher's disease, GM-I-galgliosidosis, I Cell disease, MPS I, MPS II, MPS IIID, MPS VI, Multiple Sulphatase Deficiency, Niemann-Pick (A/B), Niemann-Pick (C), Pompe's disease, Sandhoff's disease, Sialic Acid Storage disease, Wolman disease; or the first saposin comprises saposin D, and the lysosomal storage disorder is selected from the group consisting of Cystinosis, Fabry disease, Gaucher's disease, GM-I-gangliosidosis, I Cell disease, α-Mannosidosis, Metachromatic Leukodystrophy, MPS I, MPS VI, Multiple Sulphatase Deficiency, Niemann-Pick (A/B), Niemann-Pick (C), Pompe's disease, Tay-Sachs (A/B), Woman disease.