Pedigree Flashcards
(49 cards)
What were the primary goals of the human genome project
Discover complete set of human genomes
Make info accessible to for further biological study
Determine the complete sequence of DNA bases in the human genime
What is a pedigree
Specialized chart or family tree that uses a particular set of standardized symbols
What symbolizes generations
Roman numerals
How many generations is typically included on a pedigree
3
What symbolizes birth order within each generation
Arabic numbers
What are the objective of a pedigree
CAN FREQUENTLY RULE OUT BUT NOT PROVE CERTAIN MODE OF INHERITANCE
To show and analyze history of inherited traits through generations in a family
what are pedigrees helpful with
providing concise and accurate records of families
in following and diagnosing heritable traits (disease and medical conditions) by describing patterns or modes of inheritance
useful in mapping (locating and isolating) genes that are responsible for certain traits
what info needs included on a pedigree
proband
race/ethnicity
first name or initials of relatives (or generation-individual numbers can be used for confidentiality)
affected status for each indiv in pedigree
age of family members or death date (& cause)
adoption status
pregnancy/abortion (spontaneous)
consanguinity
marriage/divorce
date pedigree obtained
key to shading symbols
what is consanguinity
mating with close relatives
what is a spontaneous abortion
miscarriage
why is it important to include race/ethnicity?
certain conditions are linked to certain races and ethnicity
what is a proband
the person being studied
usually first person affected seeking medical help for possible genetic disorder
how do we note a proband
arrow with box or circle shaded accordingly
why is important to denote proband on pedigrees
in order to observe relationships bw individuals and establish patterns of inheritance
what are general guidelines to follow
start in middle of page
male to left and female partner to right w/ straight line connecting
siblings in birth order (oldest left youngest right)
use different shading to indicate multiple disorders or diseases
age
year of birth
year of death
pregnancy
alive and well
how are siblings connected
horizontal line above symbols with vertical lines connecting them
how are mates connected
straight line between them
same ancestor
consanguinity
how is consanguinity shown
mating connected by double straight lines
twins developing from single fertilized egg
monozygotic twin
are monozygotic twins different genders
no, same gender
IDENTICAL
How does monozygotic twins happen
b/c of splitting of zygote at any stage of development, even as early as the 2 cell stage
each zygote implants separaretly and has its own placenta and gestational sac
what are dizygotic twins
develop from simultaneous shedding of 2 oocytes
their subsequent fertilization by 2 different sperms
no more similar than siblins
fraternal twins
are fraternal off springs the same gender
NO
frathernal
always different genders
