6.1 Chromosomal Mutations Part 3 Flashcards
When can an amniocentesis be done?
15-22 weeks of gestation
Is there a familial link for down syndrome?
not in most cases
What is familial down syndrome?
can be generationally passed
What are the two other well known trisomys that survive to full term?
Patau and Edwards
What is Patau trisomy?
trisomy of chromosome 13
What is Edwards trisomy?
trisomy of chromosome 18
What are the symptoms of Patau trisomy?
most infants do not survive first week of life
symptoms include intellectual delays and sezuires
What are the symptoms of Edwards trisomy?
gross organ deformities
small heart
How long do those with Edwards trisomy survive?
only 10% make it to age 10
What is translocation?
the process by which a segment of chromosome is exchanged it transferred to another chromosome
What is the typical method that a chromosome gets structurally altered?
due to a break at one or more locations long the axis of the chromosome due to environmental damage
What does it mean to be heterozygous for an aberration?
if the chromosomal aberration is found on only one of the two homologs
Do those heterozygous for an aberration know they have it?
not normally
What is a deletion or deficiency aberration?
when a chromosome breaks in one or more places and the portion of chromosome is lost
What is an intercalary deletion?
when the deletion occurs within the chromosome
