1. single-gene disorders 2. chromosome disorders 3. multifactorial disorders 4. somatic cell genetic disorders 5. mitochondrial disorders 5. analyze the pedigree, what inheritance model do you think? Why? a ad b ad or Xd Section C: Consulting (50%) l Key points: Toxoplasma and birth defect. Mother 's age and Down syndrome 2. Risks of Poly gene disorders determined by ()Recurrence risk increases with the number of affected children in a family (2) Recurrence risk increases with severity of the defect. A more severely affected parent is more likely to produce an affected child. 3)Consanguinity slightly increases the risk for an affected child. (4) If the two sexes have a different probability of being affected, the least likely sex, if affected, is the most likely sex to produce an affected offspring1. single-gene disorders 2. chromosome disorders 3. multifactorial disorders 4. somatic cell genetic disorders 5. mitochondrial disorders 5. analyze the pedigree，what inheritance model do you think? Why? a AD b AD or XD Section C: Consulting (50%) 1.Key points: Toxoplasma and birth defect. Mother’s age and Down syndrome 2. Risks of Poly gene disorders determined by (1) Recurrence risk increases with the number of affected children in a family. (2) Recurrence risk increases with severity of the defect. A more severely affected parent is more likely to produce an affected child. (3) Consanguinity slightly increases the risk for an affected child. (4) If the two sexes have a different probability of being affected, the least likely sex, if affected, is the most likely sex to produce an affected offspring