| CLN2 (late-infantile NCL) | Caused by *TPP1* mutations; onset age 2–4; seizures, myoclonus, vision loss, cognitive regression |
| CLN3 (juvenile NCL/Batten disease) | Caused by *CLN3* mutations; onset age 5–10; progressive vision loss followed by seizures and dementia |
| CLN6 and CLN8 | Late-infantile variants with myoclonus and progressive neurodegeneration |
| Databases | OMIMOrphanetClinicalTrialsPubMed |