BIOLOGY Down Syndrome Case Study 1

BIOLOGY Down Syndrome Case Study 1 - 1) With your knowledge...

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1) With your knowledge of meiosis and egg formation, why should maternal age be associated with an increase in errors that lead to Down syndrome? - Researchers have established that the likelihood that a reproductive cell will contain an extra copy of chromosome 21 increases dramatically as a woman ages. Therefore, an older mother is more likely than a younger mother to have a baby with Down syndrome. However, of the total population, older mothers have fewer babies; about 75% of babies with Down syndrome are born to younger women because younger women than older women have babies. Only about nine percent of total pregnancies occur in women 35 years or older each year, but about 25% of babies with Down syndrome are born to women in this age group. The incidence of Down syndrome rises with increasing maternal age. Many specialists recommend that women who become pregnant at age 35 or older undergo prenatal testing for Down syndrome. The likelihood that a woman under 30 who becomes pregnant will have a baby with Down syndrome is less than 1 in 1,000, but the chance of having a baby with Down syndrome increases to 1 in 400 for women who become pregnant at age 35. The likelihood of Down syndrome continues to increase as a woman ages, so that by age 42, the chance is 1 in 60 that a pregnant woman will have a baby with Down syndrome, and by age 49, the chance is 1 in
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This note was uploaded on 04/19/2011 for the course BIO 21312312 taught by Professor Qe during the Spring '11 term at Philippine Normal University.

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BIOLOGY Down Syndrome Case Study 1 - 1) With your knowledge...

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