Diagnosis of<unk>  is increasingly based on assay of enzyme activity and molecular genetic testing. Thirteen pathogenic candidate genes—PPT1, TPP1, CLN3, CLN5, CLN6, MFSD8, CLN8, CTSD, DNAJC5, CTSF, ATP13A2 GRN, KCTD7—are associated with the development of the<unk> . Patients with<unk>  typically have up to 50% reduced lysosomal enzymes, and thus an enzyme activity assay is a quick and easy diagnostic test. Vision impairment is an early symptom of<unk> , and so an eye exam is another common diagnostic tool. During the eye exam, loss of cells within the eye would indicate the presence of the<unk>  however more tests are needed for a complete diagnosis. Other common diagnostic tests include: * Blood or urine test: Elevated levels of the chemical dolichol found in the urine is typical of individuals with the<unk> , as well as the presence of vacuolated lymphocytes in the blood. * Skin or tissue sampling: Microscopy of skin could be used to observe lipopigment aggregation. * CT scan or MRI: Visualization of the brain would be able to detect areas of cerebral atrophy.
Jansky–Bielschowsky disease
Camurati–Engelmann disease
Achondrogenesis type 2
Achondrogenesis type 1B
Hermansky–Pudlak syndrome
Metaphyseal chondrodysplasia Schmid type
Jansen's metaphyseal chondrodysplasia
Keppen–Lubinsky syndrome