Lecture 5: Epigenetics and Disease Flashcards
There are not just 4 nucleotides, can be _____________ to create more varietals.
There are not just 4 nucleotides, can be Methylated to create more varietals
______________: a heritable change in the pattern of gene expression that is mediated by mechanisms other than alterations in the primary nucleotide sequence of DNA
Epigenetics: a heritable change in the pattern of gene expression that is mediated by mechanisms other than alterations in the primary nucleotide sequence of DNA
Epigenetic modifications are irreversible (T/F)
False
Mechanisms of Epigenetic Regulation:
- DNA Methylation/ De-methylation.
- Numerous post-translational modifications (PTMs) of ________.
- Post transcriptional regulation of protein translation by _________ RNAs (micro RNAs).
- ______ Methylation.
- _______ regulation.
Mechanisms of Epigenetic Regulation:
- DNA Methylation/ De-methylation.
- Numerous post-translational modifications (PTMs) of Histones.
- Post transcriptional regulation of protein translation by non-coding RNAs (micro RNAs).
- RNA Methylation.
- Antisence regulation.
When located in a gene promoter, DNA methylation typically acts to ________ gene transcription
When located in a gene promoter, DNA methylation typically acts to repress gene transcription.
Histone subunits are _______ charged, thus allowing the compaction of the ________ charged DNA
Play a crucial role in what genes are and aren’t expressed
Histone subunits are positively charged, thus allowing the compaction of the negatively charged DNA
Play a crucial role in what genes are and aren’t expressed
Both genomic region compaction and gene expression are modulated by epigenetic modifications, which are deposited by specific enzymes (known as _____\_), and subsequently recognized by effector proteins (_____\_). Most, if not all, epigenetic marks are reversible, and various enzymes (“erasers”) remove these marks.
The complex interplay of these three classes of proteins controls ___________\_
Both genomic region compaction and gene expression are modulated by epigenetic modifications, which are deposited by specific enzymes (known as writers), and subsequently recognized by effector proteins (readers). Most, if not all, epigenetic marks are reversible, and various enzymes (“erasers”) remove these marks.
The complex interplay of these three classes of proteins controls gene transcription
Level 1 versus Level 2 Genes Catlogue.
Level 1: List of genes: 20-25,000
Level 2:
System overlaid on DNA in the form of epigenetic marks/ switches heritable during cell division
Determines when and where a particular gene will be
expressed during development
____________\_: The epigenetic marking of a locus on the basis of parental origin, which results in monoallelic gene expression (i.e expression from a single allele). This results in genes that are only expressed from the mother’s copy. And genes that are only expressed from the father’s copy.
Genomic Imprinting: The epigenetic marking of a locus on the basis of parental origin, which results in monoallelic gene expression (i.e expression from a single allele). This results in genes that are only expressed from the mother’s copy. And genes that are only expressed from the father’s copy.
Genetic Imprints are brought about by ______\_ instructions that are laid down in the parental germ cells
Genetic Imprints are brought about by epigenetic instructions that are laid down in the parental germ cells
______\_ is a potent growth factor so removed from removed in from maternal expression to preserve the integrity of mother with multiple offspring
IGF2 is a potent growth factor so removed from removed in from maternal expression to preserve the integrity of mother with multiple offspring
__________________________________:
- Rare Disorder in both boys and girls (1/12,000-15,000 people), presenting with a number of physical, mental, and behavioral problems.
- Constant sense of hunger that usually begins at about 2 years of age know as __________\_
- Many complications are due to obesity
- Usually diagnosed by the appearance and behaviors of a child, then confirmed by a genetic test.
- Narrow face, Almond-shaped eyes, small appearing mouth, thin upper lip with downturned corners of the mouth and full cheeks, child’s eyes may cross (________)
- Small ___________, Short stature, Hypogonadism
Prader-Willi Syndrome:
- Rare Disorder in both boys and girls (1/12,000-15,000 people), presenting with a number of physical, mental, and behavioral problems.
- Constant sense of hunger that usually begins at about 2 years of age know as Hyperphagia
- Many complications are due to obesity.
- Usually diagnosed by the appearance and behaviors of a child, then confirmed by a genetic test.
- Narrow face, Almond-shaped eyes, small appearing mouth, thin upper lip with downturned corners of the mouth and full cheeks, child’s eyes may cross strabismus
- Small hands and feet, Short stature, Hypogonadism
______________: Most common genetic cause of obesity
Prader-Willi Syndrome: Most common genetic cause of obesity
Treatments for Prader-Willi Syndrome?
- Special feeding techniques and formulas can help the infant grow
- Physical therapy and exercise help improve strength and coordination
- Administering human growth hormone improves muscle mass and growth.
- Speech therapy can help children who are behind in their language skills.
- Adopting a balanced, low-calorie diet, weight monitoring external food restriction, and daily exercise.
_________________:
- Aka. Puppet Syndrome
- Profound intellectual deficiency
- Absent _______
- _________ (small head)
- __________ gait and facial features
- __________ laughter and seizures
Prognosis?
Angelman Syndrome:
- Aka Puppet Syndrome
- Profound intellectual deficiency
- Absent speech
- Microcephaly (small head)
- Ataxic gait and facial features
- Paroxysmal laughter and seizures
- Patients become less active and have a tendency towards obesity.*
- Mobility decreases with joint contractures leading to difficulties in walking and some patients become wheelchair-bound. Life expectancy appears to be normal although autonomy is never reached.*
Management for ____________________includes:
- Physical, occupational, and speech therapy including nonverbal methods of communication
- Anticonvulsant medication is required as patients commonly develop seizures at a very young age
- A sedative medication can be given in patients with severe sleep disorders.
Management for Angelman Syndrome includes:
- Physical, occupational, and speech therapy including nonverbal methods of communication
- Anticonvulsant medication is required as patients commonly develop seizures at a very young age
- Sedative medication can be given in patients with severe sleep disorders.
Prader-Willi Syndrome is associated with the loss of _____________ chromosome ______________
Prader-Willi Syndrome is associated with the loss of Paternal chromosome 15q
Several genes appear to be involved in Prader-Willi. One of these genes, SNRPN, encodes a small nuclear riboprotein that is expressed in the brain. These genes are only active/expressed on the chromosome inherited from the Father enforced by epigenetic tags. Thus a Paternally inherited deletion removes the single active/expressed copy of the gene.
Angelman Syndrome is associated with the _______________loss of chromosome ____________
Angelman Syndrome is associated with the Maternal loss of chromosome 15q
Complete Hydatidiform Mole [CHM] results from Diploid ______ Genome
Complete Hydatidiform Mole [CHM] results from Diploid Paternal Genome
Cystic Teratoma of the Ovary Diploid ______\_ Genome
Cystic teratoma of the Ovary Diploid Maternal Genome
_______________________:
- Incidence of 1 in 13,700 births
- Pre and postnatal overgrowth up to 160% of normal birth weight
- __________\_ (enlarged, often protruding tongue)
- __________\_ (enlarged organs)
- __________\_ (large hole in the abdomen with skin missing, part of the bowel on the outside)
- Increased risk of _________________ development
Prognosis?
Beckwith-Wiedemann Syndrome (BWS):
- Pre and postnatal overgrowth up to 160% of normal birth weight
- Macroglossia (enlarged, often protruding tongue)
- Visceromegaly (enlarged organs)
- Exomphalos (large hole in the abdomen with skin missing, part of the bowel on the outside)
- Increased risk of Tumour development
- Many children with BWS grow up to have healthy adult lives, a normal lifespan, and they can have healthy children.
- Although a child with BWS may have larger features than their peers, their growth rate decreases as they age, as does their risk of developing cancer
Imprinting implications of ___________________________\_:
- Paternal trisomy of 11p15.5
- Paternal UPD (isodisomy) of 11
- Paternal duplication of the 11p15.5 region
Imprinting implications of Beckwith-Wiedemann Syndrome (BWS):
- Paternal trisomy of 11p15.5
- Paternal UPD (isodisomy) of 11
- Paternal duplication of the 11p15.5 region
___________________leads to more genes exposed increasing transcriptional activity for cancer cells.
Cancer cells also experience _________ for genes involved with apoptosis turned off by methylation
Hypomethylation (less methylation) leads to more genes exposed increasing transcriptional activity for cancer cells
Cancer cells also experience Hypermethylation for genes involved with apoptosis turned off by methylation
