医学遗传学14章总结(英文班).doc

Chapter 14 chromosomal diseases
1 . Chromosome disease: Any syndrome characterized by malformations or malfunctions in any of the body's systems, and caused by abnormal chromosome number or constitution.
2、Clasification:
Autosomal disease常染色体病:Several serious human disorders are due to alterations of autosome number and structure.
Sex chromosomal disease性染色体病:Some disorders are caused by abnormal sex chromosome number and structure.
Autosomal disease常染色体病
Down’s syndrome ,Trisomy 21 syndrome 21三体综合征/先天愚型
【1】Incidence发生率
Incidence:1/1000~2/1000
The probability increases with maternal age 随母亲生育年龄增高而增高
【2】clinical characteristics
Special facial appearance
a broad head and a very round face.
an upward slant to the eyes, widely-spaced eyes
a flat nasal bridge 鼻梁扁平
a protruding tongue 舌外伸
Ears: The ears are small with an overfolded helix.
Developmental delays 发育迟缓
Short stature and obesity 矮胖
Poor muscle tone 肌张力弱
sitting up, crawling, and walking — later than other kids
Toddlers初学走路的孩子 and older kids may have delays in speech and self-care skills like feeding, dressing
Mental retardation 智力缺陷
in the mild (IQ 50–70) to
moderate (IQ 35–50) range
Shorter and bounty hands 短而宽的手
Dermatology皮肤病:Simian crease
A single transverse palmar crease. 断掌
Normal 2%
Abnormal 50%
Atd angle>58° normal<41°
Straw sandal foot:
excessive space between large toe a