| Disease / synonyms | Inheritance | Causal gene / IDs | Locus | Key papers (date; URL) | Key clinical hallmarks | Typical onset range | Citations |
|---|---|---|---|---|---|---|---|
| Autosomal Recessive Cerebellar Ataxia–Saccadic Intrusion Syndrome; Spinocerebellar ataxia with saccadic intrusions (SCASI); Spinocerebellar ataxia, autosomal recessive 4 (SCAR4); formerly SCA24 | Autosomal recessive | **VPS13D**; disease **SCAR4 OMIM #607317**; gene **VPS13D OMIM *608877** | 1p36 | Seong et al., **2018-06**, *Ann Neurol*; https://doi.org/10.1002/ana.25220 • Kistol et al., **2024-05**, *Int J Mol Sci*; https://doi.org/10.3390/ijms25105127 | Progressive cerebellar ataxia, spasticity/pyramidal signs, saccadic intrusions/ocular-motor abnormalities, neuropathy; some cases with developmental delay or loss of ambulation | Infancy to adulthood; reported from **<1 year to 39 years** | (pqac-00000003, pqac-00000004, pqac-00000025) |
| Historical family-based SCASI description before gene identification | Autosomal recessive | Gene not yet identified in 2003 family report; later resolved as **VPS13D** | Linked to chromosome **1p36** in later studies | Swartz et al., **2003-12**, *Ann Neurol*; https://doi.org/10.1002/ana.10758 • Akbar & Ashizawa, **2015-02**, *Neurol Clin*; https://doi.org/10.1016/j.ncl.2014.09.004 | Progressive ataxia with difficulty reading, macrosaccadic oscillations/saccadic oscillations intruding on fixation, pyramidal signs, myoclonus, axonal sensorimotor neuropathy, pes cavus; mild cerebellar vermis atrophy reported | Review/table source lists **3rd decade** onset for SCASI; family studies support slow progression | (pqac-00000013, pqac-00000002) |
| VPS13D-related disorder spectrum encompassing SCAR4/SCASI | Autosomal recessive (usually biallelic, often compound heterozygous) | **VPS13D**; representative pathogenic variants include **c.3569G>A (p.Gly1190Asp)**, **c.3316C>T (p.Gln1106Ter)**, **p.Tyr1803Ter**, **p.Ala4210Val**, **c.2237-1G>C**, **c.941+3A>G**, **c.9998+4A>C**, **c.9388C>T (p.Arg3130Ter)**, **c.9679G>T (p.Gly3227Trp)** | 1p36 | Seong et al., **2018-06**, https://doi.org/10.1002/ana.25220 • Pauly et al., **2023-01**, https://doi.org/10.3390/ijms24031874 • Kistol et al., **2024-05**, https://doi.org/10.3390/ijms25105127 | Ataxia-spasticity spectrum with dysarthria, tremor, dystonia/chorea in some patients, saccadic pursuit or square-wave/macro-saccadic intrusions, peripheral axonal neuropathy, variable cognitive/developmental involvement; mitochondrial abnormalities in fibroblasts support mechanism | Broad range from early childhood/infancy to adult-onset; slowly progressive | (pqac-00000007, pqac-00000008, pqac-00000010, pqac-00000017) |


*Table: This table compacts the key identifiers, genetics, landmark papers, and hallmark clinical features for autosomal recessive cerebellar ataxia–saccadic intrusion syndrome. It is useful as a quick-reference scaffold for a disease knowledge base entry focused on VPS13D-related SCAR4/SCASI.*