chromosomal polysomies and epigenetic diseases 4-2 Flashcards
defect of down’s syndrome
trisomy of chr 21, usually from multiple copies in the egg from nondisjunction during meisosis I or gametogenesis
features of Down’s syndrome
extra copy of APP, epicanthal eye folds, flat nasal bridge, railroad track ears, smooth philtrum, heart disease, enlarged colon, heart disease
defect of Klinefelters
XXY
Turner’s Syndrome defect
XO
features of Turner’s Syndrome
neck webbing, ovaries lacking, stunted growth, female genitals,
features of Klinefelter’s Syndrome
small male genitalia, sterile except for in vitro
2 treatments for Turner’s
growth hormone (can decrease body fat), neck fold surgery
3 treatments for Klinefelter’s
testosterone supplementation, in vitro, sex change hormone treatment and surgery
two covalent modifications for chromatin accessibility
methylation decreases access, acetylation opens access
epigenetic mechanism that allows cancer cells to grow
hypermethylation decreases tumor suppressor and DNA repair gene expression, opposite of oncogenes
silencing of chromatin (as in cancer)
mediated by histone deacetylases
What inhibitors can improve cancer progression
histone deacetylase (HDACs) and DNA methyl transferases (DMNTs)
features of Willi-Prader
hypertonia, eating disorders that change over time
features of Angelman
hypertonia, jerky uncoordinated movements, unprovoked smiling and laughter
difference of Willi-Prader and Angelman
On chr 15, large region of genes are deleted in the paternal chr of Willi-Prader that are epigenetically silenced on the maternal chromosome, on the maternal chr genes of Angelman that are normally epigenetically silenced on the paternal chromosome
