Table 1
Characteristics of the presenile dementia syndromes
| Type | Abnormal protein | Predisposing genetic mutations | Susceptibility genes | Per cent of predisposition mutations |
|---|---|---|---|---|
| Alzheimer | Amyloid β-42 | Amyloid precursor protein, presenilin 1, presenilin 2 | Apolipoprotein E4 | <5% |
| Frontotemporal dementia | Tau | Tau introns and exons | Unknown | <10% |
| Dementia with Lewy bodies | α Synuclein | α Synuclein, 4p locus | Apolipoprotein E4 | <1% |
| Creutzfeldt–Jakob | Prion | Prion protein | Prion protein codon 129 | <15% |
