Steps
- Identify the families
- Mum, Dad and children.
- Write XX or XY
- Try to determine if they are affected, unaffected or a carrier.
- Is it Recessive?
- Unaffected parents can have affected children. This means the parents would have heterozygous genotypes.
- Recessive can skip a generation.
- Is it Sex-linked Recessive or Autosomal Recessive?
- If both sexes have the trait - Autosomal.
- Is it X or Y linked?
- If all males are affected - Y linked.
- If disorder transfers from Mother to (all of her) Son but never transfers from Father to Son - X linked.