1. The Blue People of Kentucky

2. Troublesome Creek in Eastern Kentucky
Isolated hill country
Local people married relatives
Passed rare, recessive disease to offspring

3. Methemoglobinemia Recessive allele for gene on chromosome 22
Diaphorase enzyme deficiency
Reduces oxygen carrying capacity of red blood cells
Causes cyanosis (bluish color of skin), shortness of breath, and heart disease

4. Fugate Descendants

5. Fugate Pedigree
Complete Fugate Pedigree Analysis using these genotype symbols:
BB = unaffected individuals
Bb = carriers
bb = affected individuals

6. Pedigree of the Blue People of Troublesome Creek, Kentucky
Square = male
Circle = female
Horizontal connecting line = parents
Double connecting line = marriage between close blood relatives
Vertical line = offspring
Filled in = affected individual
Half filled = carrier (heterozygous)