ACB 330 Lecture Notes - Lecture 24: Cleft Lip And Cleft Palate, Microphthalmia, Pubic Hair
6 Apr 2018
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Document Summary
Serious defects occur in 40-50% of all early embryos. Fail to separate during 1st or 2nd meiotic division. Zygote obtains extra copy or is short 1. Brain and sc defects, heart issues, cleft palate, micropthalmia. Tri of sex chromosome: xxy genotype: klinefeter: femiine physique, small testis, female pubic hair. Mono of x: turner syndrome: elbow issues, no menses, wide nipples, fold of skin: usually lethal. Polyploidy: embryonic cells have >3x the haploid number, abort or are still born. Breakage defects: due to radiation, chemical or virus. Cri du chat: deletion at end of short arm of chromosome. : microencephaly, mental retardation, heart defects, weak cat like cry. Achondroplasia: gain of function in fgfr-3 gene: dwarfism. Male female sex reversal in xy fetus: due to lack of sox9 gene. Environmental factor capable of increasing the chances of congenital malformation. Radiation: damages chromosome: mutates genes: inhibits cell proliferation: high doses: spina bifida, microencephaly, cleft,
