Download Making a Pedigree Chart - Kyrene School District

Making a Pedigree
Chart
A family history of a genetic
condition
Quick Review
1. Genotype = a description of genes (two alleles)
inherited for a particular trait
2. Dominant genes are usually
represented by: a capital letter
3. Lower case letters are used for: the recessive allele.
a allele
4. For every trait, you get an _______from
each
parent.
5. The genes you inherit are determined
____________.
randomly
Making a Pedigree Chart
• Pedigree charts are
made to chart family
history and see how
traits are passed
• A genetic counsellor
will use pedigree
charts to help
determine the
distribution of a
disease in an affected
family
Symbols
• Shade individuals
that have the trait
you’re studying
• Boys = squares
(Lucy always calls
Charlie Brown a
‘block head’)
• Girls = circles
• Married-connected at
side
• Siblings-connected at
TOP not at the side
(hopefully not siblings
AND married)
• Oldest child-to the
left
• Question-if shaded
individuals in this
pedigree have blue
eyes, what is the
GENOTYPE of the
parents?
Other
• Divorced,
separated
• Deceased
• Identical twins
• Fraternal twins
Organizing the pedigree
chart
Generations are identified by Roman
numerals
I
II
III
IV
Organizing the pedigree
chart
• Individuals in each generation are identified
by Arabic numerals numbered from the left
• Therefore the affected individuals are II3,
IV2 and IV3
I
1
II
III
IV
2
3
4
5
6
7
Flipnob Dimples
• This is the story of Grandma and
Grandpa Flipnob, and their clan! They
were married way back in 1933, and
have been just like newlyweds ever
since.
Flipnob Dimples pg 2
• From their union, 4 individuals were
created. Elizabeth, the eldest, was
born in 1935. Fred soon followed in
1936. In 1939 Michelle was brought
into this world. Mickey (a surprise to
the whole family) was the baby of
the family, not being born until 1950.
Flipnob Dimples pg 3
• Elizabeth fell in love at a young age,
and wed her high school sweetheart,
David, in 1954. From this marriage,
two bundles of joy came about (at
the same time):
• John and Sonny - 1955 (twins)!
Flipnob Dimples pg 4
• It took Fred a little longer to find
his soul mate. Finally in 1970, Fred
found the woman of his dreams,
Wilma, and they were married. Since
they married so late in life, they only
brought one new person into this
world:
• Barney - 1972
Flipnob Dimples pg 5
• Michelle was a hard working woman,
and never found time in her schedule
for love. She led a very productive
and fulfilling life, but she never did
marry and have children.
• Answer the following questions
regarding your pedigree:
• 1. Who are the inlaws?
• 2. What is the relationship between
Flipnob Dimples
From their union, 4 individuals were
created. Elizabeth, the eldest, was
born in 1935. Fred soon followed in
1936. In 1939 Michelle was brought
into this world. Mickey (a surprise to
the whole family was the baby of the
family, not being born until 1950.
Flipnob Dimples
• Elizabeth fell in love at a young age,
and wed her high school sweetheart,
David, in 1954. From this marriage,
two bundles of joy came about (at
the same time):
• John and Sonny - 1955 (twins)!
Flipnob Dimples
• It took Fred a little longer to find
his soul mate. Finally in 1970, Fred
found the woman of his dreams,
Wilma, and they were married. Since
they married so late in life, they only
brought one new person into this
world: Barney - 1972
Flipnob Dimples
• Michelle was a hard working woman,
and never found time in her schedule
for love. She led a very productive
and fulfilling life, but she never did
marry and have children.
Flipnob Dimples
• Mickey was a wild one!! After a long
string of girlfriends, he finally chose
Monica to spend the rest of his life
with. They were wed in 1975 and
brought two girls into this world:
• Krista - 1977
• Janet - 1979
Flipnob Dimples
Make sure you have the Generations
marked and the indivduals numbered.
1. Who are the in-laws?
2. What is the relationship between
the people in the third generation?
Flipnob Dimples
• Now that you have your pedigree
chart together, shade the
appropriate circles and squared from
the information to follow. Remember
that individuals who possess the
RECESSIVE trait are to be filled in.
Those individuals not filled in possess
at least one dominant trait.
Flipnob Dimples
• Now that you have your pedigree
chart together, shade the
appropriate circles and squared from
the information to follow. Remember
that individuals who possess the
RECESSIVE trait are to be filled in.
Those individuals not filled in possess
at least one dominant trait.
Flipnob Dimples
• Not having freckles is a recessive
trait.
• Grandpa Flipnob did not have
freckles, but his beautiful bride did.
• Fred and Michelle were the only two
of their siblings to have freckles.
• Of the grandchildren, the twins did
not have freckles, and neither did
Barney, but the two girls did.
• GUIDE
• STEP 1
• Assign two recessive genes to any
person on the pedigree whose symbol
is shaded. Small letters are written
below the person s symbol.
• GUIDE
• STEP 2
• Assign one dominant gene to any
person on the pedigree whose symbol
is unshaded. A capital letter is
written below the person s symbol.
Add a short black line next to the
capital letter.
• GUIDE
• STEP 3
• Use the information given to you to
determine the second alleles for each
person with the dominant phenotype.
Autosomal – Approx.
50/50 affected
http://www.slideshare.net/aus_autarch/pedigree-chartspowerpoint-presentation
Dominant– One parent
has the disorder
Recessive – Neither parent needs to have the
disorder they can be heterozygous
What’s going on?
Shaded = blue eyes
• 1 and 2 split after
having 4, 2 then had
kids with 3 and split
with her too after 5-9
were born
• Genotypes of 1, 4,7?
• Genotypes of 2 & 3?
• Genotypes of 5,6, 8, 9,
10, 11, 12?
Make your own pedigree
• Using your own family, make your own
pedigree chart
• Must at LEAST include grandparents,
parents, & your generation
• Pick one easy dominant or recessive trait
and shade individuals that have it. You
can guess who has it if you don’t know for
sure. (Don’t pick a trait that EVERYONE
in your family has)
• Label yourself, grandparents, cousins, etc
• Put a key on the pedigree so I know
what shaded means. Ex.- shaded people
have widow’s peak
OR…you may create a pedigree chart for a
fictional family of your choice. For
example, a family in a book you read or a
movie you have seen (ex: Twilight series,
Harry Potter, etc)