医学遗传学双语练习（单基因遗传）
（此练习旨在帮助同学们了解英文题目）
Short-answer Questions简答题(用中文答题)
1. Draw a simple pedigree of three generations of a family to illustrate the transmission of an X-linked recessive disorder. (提示：注意XR遗传的特点)
2. List three differences between autosomal dominant inheritance and autosomal recessive inheritance.（提示：对比两种遗传方式的特点）
3. State the characteristics of X-linked dominant inheritance.
4. Explain what is meant by incomplete inheritance, with example.
5. Explain what is meant by expressivity, with example.
（此练习旨在帮助同学们了解英文题目）
Analysis and calculation 分析与计算(用中文答题)
1．Cathy is pregnant（怀孕）for the second time．Her first child，Donald，has CF(囊性纤维化)．Cathy has two brothers，Charles and Colin，and a sister，Cindy．Colin and Cindy are unmarried．Charles is married to an unrelated woman，Carolyn，and has a 2-year-old daughter，Debbie．Cathy’s parents are Bob and Betty．Betty’s sister Barbara is the mother of Cathy’s husband，Calvin，who is 25. There is no previous family history of CF．
a．Draw the pedigree，using standard symbols．
b．What is the pattern of transmission of CF，and what is the risk of CF for Cathy’s next child?
c．Which people in this pedigree are obligate heterozygotes (杂合子)?
d．Who is the proband in this family? What are the genotypes (基因型)of the proband and his/her parents?
2. The frequency of Tay-sachs(台萨斯）carrier is 1 /100 in a population.
(1)A couple with normal phenotype is unrelated. What is the risk of Tay-sachs disease for the
children of this couple?
(2)A normal man is married to his first cousin. What is the risk of Tay-sachs disease for the
children of this couple?
3. A positive carrier(肯定携带者) of albinism(白化病）marries his first cousin. What is the risk of their children？
4. Don and his maternal grandfather（外祖父）Barry both have hemophilia A（血友病A）. D on’s partner Diane is his maternal aunt’s daughter. Don and Diane have one son, Edward, and two daughters, Elise and Emily, all of whom have hemophilia A. They also have an unaffected daughter, Enid.
a. Drew the pedigree
b. Why are Elise and Emily affected?
c. What is the probability (概率) that a son of Elise would be hemophilic? What is the probability that her daughter would be hemophilic?
d. What is the probability that a son of Enid would be hemophilic? A daughter ?
5. Pedigree analysis (系谱分析)：①Judge the inheritance patterns of pedigrees and the genotypes (基因型)of the proband and his/her parents.②Gave your reason for judgement.
(系谱详见《医学遗传学讲授提纲》P45-46)
