The first two weeks of class touched on the development of the fetus, from conception to delivery. This included the Developmental period, Abortion and Live Birth.
A good amount of time was spent on NONDISJUNCTION (Abnormalities in chromosome where pairs of homologous chromosomes fail to separate during 1st or 2nd meiotic division). When this occurs, one daughter cell receives 24 chromosomes and other receives 22 chromosomes instead of the normal 23. Also, women age 35+ have increased incidence of chromosomal abnormalities including chromosome nondisjunction. This was one of the discussions in class where some students wanted to know why this was the case (there is no known reason exactly why there is an increase in chromosomal abnormalities in the eggs of women as they age. However, research studies have shown that during meiotic division, the eggs of older women have a higher risk of not dividing properly in the meiotic spindle.
Turner’s syndrome (monosomy x, 45 x 0) was one of the most talked about chromosomal abnormality in class as the students were fascinated by its clinical features.
Turner’s syndrome is the only monosomy compatible with life.98% of fetuses with the syndrome are spontaneously aborted and the few that survive are unmistakably female in appearance characterized by absence of ovaries and short stature.
Other characteristics include webbed neck, lymphedema of the extremities, skeletal abnormalities and road chest with widely spaced nipples. About 55% affected females have monosomy X and have no Barr body because of nondisjunction.
With all, there was a lot of interactions and engagement in the class and this was reflected on our first quiz (high pass rate). Looking forward to next week and the rest of the semester.