Epigenetics/Imprinting Flashcards Preview

M2M - Genetics > Epigenetics/Imprinting > Flashcards

Flashcards in Epigenetics/Imprinting Deck (3)
Loading flashcards...
1
Q
  • Epigenetics def? Ex?
  • Imprinting?
  • Molecular basis of imprinting? In transcription region? Effects? (2) How?
A
  • Heritable change in gene expression with out change in DNA sequence (such as post translational change to histones)
  • Silencing of autosomal genes aka turned to hemizygotes
  • methylation of promotes in 1 of 2 germlines; doesn’t have to be
    1. ) Silencing –> Methylation repels TF’s or attracts repression factors
    2. ) Activation –> Repels repressors
2
Q
  • 3 rules of imprinting?
  • How do somatic cells keep add methylation after synthesis? How about germ lines?
  • Examples of contiguous gene (micro deletion) syndromes related to this? Syndromes?
A
  1. ) Modification occurs when gametes seperate
  2. ) Stable after fertilization
  3. ) Erased when producing germ cells
    - Maintenance methyltransferase; denovo methyl transferase
  4. ) Prader willi = deletion of paternal long 15 = obesity, hypogonadism, almond eyes, sleep apnea (containdication to use GH)
  5. ) Angelmans = Deletion of maternal long 15 = unusual face, seizures, spacicity
3
Q
  • IDIC? Symptoms?
  • Interstitial 15q duplications?
  • Downs: Common reason? Amniotic fluid situation? Symptoms? Tests to check = 1st trimester? 2nd? 16 weeks?
A
  • 15q effected, autism, seizures, hypotonia
  • Autism if mothers copy only, seizures
  • Trisomy 21, extra fluid; brushfield spots, GI tract and heart issues, increased risk of leukemia
    1. ) ultrasound for nuchal folds
    2. ) quad screen
    3. ) Amniocentesis for karyotype