| Prevalence | Approximately 1 in 1,000,000 to 1 in 4,000,000 live births worldwide 6 |
| Type I (cherry-red spot myoclonus) | More common than type II, typically presenting in the second or third decade of life |
| Type II (infantile/juvenile) | Rarer, with earlier onset and more severe phenotype |
| Gender distribution | Equal male and female prevalence (autosomal recessive inheritance) |
| Geographic distribution | Worldwide, with higher reported prevalence in populations with higher rates of consanguinity |
| Ethnic clustering | Some populations show founder effects leading to local clustering of cases 7 |
| Missense mutations | The most common type, often resulting in reduced enzyme stability or activity |
| Nonsense mutations | Creating premature stop codons and truncated proteins |
| Splice-site mutations | Leading to exon skipping or intron retention |
| Small deletions/insertions | Causing frameshifts and premature termination 9 |
| Databases | OMIMOrphanetClinicalTrialsPubMed |