细胞生物学英文课件-72 染色体畸变(数目改变)

Chromosomal Abnormalities

(染色体畸变)

Chromosomal abnormalities can be of two types.

(1)Structural (结构) abnormalities: including

Deletions, Deletions, Duplication, Translocation

(1) Numerical(数目) abnormalities: caused by gain

or loss of chromosomes.

Alterations in chromosome

number 一、Alterations in sex chromosome number

（教材上册p142）

Turner Syndrome (45, X)

性

腺发育不全综合

1 in 2500 liveborn

females Characteristics

o

Short stature & Webbed neck

o

Ovarian dysgenesis, primary amenorrhea, infertility o

Absence of secondary sex characteristics

o

Underdeveloped breasts;

wide nipples

症身材矮，蹼颈，肘外翻，原发性闭经，生殖器幼稚，索状性腺（结缔组织，无卵泡）。成因：早期卵裂过程中染色体不分离。