文档介绍：03 疾病的单基因遗传Monogenic Inheritance
single-gene disorder or
monogenic disorder

Some disorders result when a mutation causes the product of a single gene to be altered or missing. These disorders are inherited in simple patterns similar to or identical with those described by Mendel for certain discrete characteristics in garden peas. Therefore, it’s also called Mendelian diseases.
3
☆病例分析
姓名:不幸××
男性,69岁,已3次经中南大学湘雅二医院临床确诊异时性结直肠癌,即52岁时诊断为右半结肠癌,61岁发生乙状结肠癌,68岁患直肠癌。
家族史:先证者的儿子于25岁和37岁两次诊断为异时性结直肠癌。其家族4代31人中有17人共21例次诊断结直肠癌等恶性肿瘤,其中12名( %)患者患有结直肠癌, 另6名患者发现结直肠外恶性肿瘤,包括子宫内膜、胃、脑、肝脏等。所有患者恶性肿瘤的平均发病年龄是41岁, , 患者的男女性别比例是10∶7。
1. Pedigree and Proband
Humans are unique anisms in many ways, but one way which is near and dear to a icist's heart is that humans are not susceptible to ic experimentation.
The study of inherited Mendelian traits in humans must rely on observations made while working with individual families.
Classical cross fertilization breeding experiments as performed by Mendel are not allowed in humans! Human icists are not allowed to selectively breed for the traits they wish to study!
One of most powerful tools in human ic studies is pedigree analysis.
pedigree
They are graphic representations of a family tree which show the biological relationship of the index case, or proband or propositus to the rest of the individuals.
A family tree diagram that shows how a particular ic trait or disease has been inherited.
When human icists first began to publish family studies, they used a variety of symbols and conventions. Now there are agreed upon standards for the construction of pedigrees.
Symbols