1. Pedigree Drawing and Analysis Starts with the person through whom the family came to medical (genetic) attention Has a codified shorthand Standardization of symbols generally adopted Information obtained historically or by ongoing evaluation –updatable –allows a pattern of inheritance of a trait to be determined –useful for linkage analysis (see later lecture)

2. Male Female Phenotypic/genotypic affected Used to mark the proband (index case) Lines are used to link individuals Horizontal lines between symbols denote mating Vertical lines mark parent/child relationships Birth order is left = oldest, right = youngest Twins have special notation Sex unknown Numerals in symbols indicate number of sibs of same sex

3. Roman Numerals indicate Generations Arabic numerals identify individuals within a generation 12 II 23 I 14

4. 12 23 I 14 III

5. What is the inheritance pattern and why?

6. What pattern of inheritance is shown?

7. What additional information might molecular, biochemical or chromosomal techniques reveal?

8. What pattern of inheritance is present? Can additional information be deduced about individuals in each generation?

11. X linked lethal? or X-linked recessive?

12. The pedigree indicates the individuals who have had symptoms of acute porphyria.

13. However, biochemical testing reveals this pedigree. What principle is being demonstrated?

14. What pattern of inheritance is present? What can you tell person III 4?