L01-2
Which type of genomic imprinting occurs that causes silencing of genes due to hypermethylation?
epigenetic changes
A balanced carrier of a translocation shows no phenotype. Therefore has a derivative chromosome, abbreviated as dr. Does this person have a phenotype? What about their progeny?
This person who is a balanced carrier would have no phenotype but their progeny may be affected
Which type of chromosome results in their offspring being 100% affected?
ISOCHROMOSOME
What chromosome type occurs as an abnormal fusion of 2 chromosome pieces, each of which has a centromere. Results in a loss of genetic material
dicentric chromosome
Uniparental disomy occurs when
offspring inherits 2 copies of chromosome from a single parent
What is the term that describes this: offspring inherits two different copies of same chromosome from a single parent in nondisjunction in meiosis I, offspring inherits homologs
heterodisomy
Explain what a Translocation is
exchange of genetic material between non homologous chromosomes
A parental karyotype ends with: rob(13;14) (q10:q10). What could their progeny have? Is it viable?
Trisomy 13, which is viable OR could have progeny with Trisomy 14, which is unviable
True or false: Trisomy 18 could result from an imbalance, duplication, or translocation
true
What term is being defined: offspring inherits two copies of chromatid from a single parent, occurs as a result of nondisjunction in meiosis II or monosomy rescue
isodisomy
How do you most often detect a structural change to chromosomes?
You detect it in the affected offspring
On which chromosomes would you see a robertsonian translocation
13,14,15,21,22
Which inversion type changes size of arms?
pericentric inversion
Which trisomy would be a carrier of rob(13q:15q)
trisomy 13
What is the treatment for Prader Willi?
Growth hormone and low cal diet with excersize
If a child has Prader Willi, what is not getting expressed? (be specific)
no expression of snoRNA because there is no paternal copies of chromosome 15
This karyotype shows: 46,XX,-14, + rob(14q;21q)
trisomy 21
This karyotype shows: 46,XY, del (22q11)
DiGeorge
Why do robertonsian translocation carriers have no phenotype
loss of short arms and they contain no essential genetic information
In a person who has Angelman syndrome, what do they not express? (be specific)
no expression of UBE3A because they have no maternal copies
What are the maternal and paternal consequences of uniparental disomy?
paternal UPD: angelman syndrome (loss of maternal expression)
maternal UPD: prader willi syndrome (loss of paternal expression)
A male who has Angelman syndrome reproduces. What will his offspring have?
Prader-Willi
What is the leading cause of structural damage to chromosomes?
segmental duplication
What is significant about this karyotype? 46,XY,+i (12p)
The progeny are at 100% risk
Name the acrosomal chromsomes
13,14,15,21,22