Alzheimer's DiseaseComplex polygenic (early-onset: autosomal dominant)Heritability: 60-80%
APPPSEN1PSEN2APOEAPOE e2PLCG2ABI3
Parkinson's DiseaseComplex polygenic with monogenic subtypesHeritability: 25-40%
LRRK2GBASNCAPARK2 (protective alleles)HLA-DRB5
Amyotrophic Lateral Sclerosis (ALS)Oligogenic (familial) / Complex (sporadic)Heritability: 40-60%
SOD1C9orf72TBK1TARDBPFUSUNC13A (protective alleles)
Sickle Cell DiseaseAutosomal recessive (single gene)Heritability: 100% (single gene)
HBB
Cystic FibrosisAutosomal recessive (single gene, allelic heterogeneity)Heritability: 100% (single gene)
CFTR
Huntington's DiseaseAutosomal dominant (trinucleotide repeat expansion)Heritability: 100% (single gene)
HTT
Breast CancerComplex polygenic (with high-penetrance monogenic subtypes)Heritability: 30-40%
BRCA1BRCA2BRCA1 (protective alleles)RAD51 variants
Type 1 DiabetesComplex polygenic (HLA-dominant)Heritability: 50-60%
HLA-DRB1HLA-DQB1INSPTPN22HLA-DRB1*15:01HLA-DQB1*06:02
