Misc. 1 Flashcards
What does GINA protect?
- employment
- health insurance
What does GINA not protect?
- life insurance
- disability
- long term care
For GINA, what is not considered genetic info?
- sex
- age
- routine tests
- DNA of infectious agents
- pre-existing conditions (even if they are genetic)
For HIPAA, what geographical identifiers are protected?
anything smaller than state (ie county, zip code, etc)
Retinitis pigmentosa
- description
- cause
- abnormalities in rods, cones, or retinal pigment epithelium lead to progressive visual loss in early adulthood
- caused by mutations in >50 genes
Age-related macular degeneration
- description
- cause
- vision loss late in life
- multifactorial; many genes may be implicated
What is the most common UPD mechanism?
trisomic rescue
What arm(s) do pericentric inversions involve?
both
What arm(s) do paracentric inversions involve?
one
What is an example of a common pericentric inversion that is a polymorphism?
inv(9)(p11q13)
Does it matter from which parent the extra material in triploidy comes from?
yes
What is the recurrence risk for a reciprocal translocation when a parent is a carrier? Exceptions?
~20%
but 9p and distal 4p and 5p hvae a higher recurrance risk of ~30%
What is pachytene?
crossing over
What percentage of inversions are inherited?
90%
For what type of cancer does external beam radiation increase risk?
osteosarcoma
What isolated fetal ultrasound finding is most likely due to a chromosomal abnormality?
cystic hygroma
What percentage of balanced reciprocal translocations are inherited?
70%
Name the trinucleotide repeat disorders
- Huntington
- SCA
- DRPLA
- Kennedy
- Fragile X
- Friedreich’s ataxia
- Myotonic dystrophy
What is the Hardy-Weinberg equation?
p^2 + 2pq + q^2 = 1
Name 2 conditions with overgrowth
- Sotos
- Beckwith-Wiedemann
Name 3 conditions with dysmorphic features but normal intellect
- Beckwith-Wiedemann
- Crouzon
- Saethre-Chotzen
Name 5 conditions with absent speech
- Phelan-McDermid
- Rett
- 1p36 deletion
- Angelman
- Mowat-Wilson
Name 2 conditions with sparse hair findings
- Pallister-Killian
- Sotos
Name 2 conditions with self-injurious behavior
- 1p36 deletion
- Smith-Magenis
Name 2 conditions with a friendly demeanor
- Angelman
- Williams
Name 3 conditions with regression / loss of milestones
- Tay-Sachs
- Rett
- Menkes
Name 2 conditions associated with ATP7_ genes
- Menkes
- Wilson
heritability - definition
the fraction of total phenotypic variation of a trait that is caused by genes
heritability - equation
(%MZ concordance - %DZ concordance) / (100 - %DZ concordance)
Which chromosomes have imprinted genes?
- 6 (neonatal diabetes)
- 7 (growth restriction)
- 11 (Beckwith/Russel)
- 14 (skeletal anomales)
- 15 (Prader/Angel)
How many genes does mitochondrial DNA encode?
37
Which organs are most commonly effected by mitochondrial mutations?
those with high energy demands:
- muscle
- heart
- brain
Are the effects of monosomy or trisomy typically more severe?
monosomy
What is a Robertsonian translocation?
A reciprocal translocation where the long arms of 2 acrocentric chromosomes fuse at their centromeres
Name 6 syndromes resulting from mitochondrial mutations
- Leber’s optic atrophy
- MELAS
- MERRF
- Kearns-Sayre
- Pearson
- Leigh
What percentage of cases of Down syndrome are due to 47 chromosomes?
95%
