Hardy-Weinberg Analysis
Codominance
both alleles contribute to the phenotype of the heterozygote
E.g Blood groups; alpha1-antitrypsin deficiency
Variable expressivity
phenotype varies among individuals with same genotype
Eg. 2 pts with NF may have varying disease severity
Penetrance
the proportion of individuals with a given genotype that express the associated phenotype.
In incomplete or reduced penetrance, <100% of individuals with a given genotype express its associated phenotype.
E.g. BRCA1 gene mutations do not always result in breast or ovarian cancer