8.7- Pedigree Analysis

Pedigree chart:

a diagram that illustrates how genetic traits are passed down over generations of related individuals. Useful in determining unknown genotypes and inheritance patterns.

Consanguinity:

inbreeding/incest. Represented on a pedigree by double horizontal lines between individuals. Increases likelihood that recessive conditions will be inherited. Key identifiable observations for common inheritance patterns: 

Autosomal Dominant

• Does not Skip Generation

• Equally affects both genders

• Two unaffected parents cannot have affected offspring 

Autosomal Recessive

• Skips Generations

• Equally affects both genders

• Two unaffected parents have affected offspring 

X-linked Dominant

• Does not skip generations

• Yes equally affects both genders

• All daughters of an affected father will be affected. 

X-linked Recessive

• Yes, skips generations

• No, does not equally affect both genders

• Affected mothers will have affected sons.

• Normal father will never have affected daughters