Transcript h - Cloudfront.net

• Genetic pedigrees are like family trees
• They show relationships, but also can track traits
throughout a family
• Squares = male; Circles = female
• Shaded = has the trait (usually a disease)
• Let’s create a simple pedigree…using PKU as an
example
• PKU is a recessive disease where sufferers lack a
protein needed to properly digest foods. It can be
fatal if untreated.
Creating a Pedigree
Key
Hh
Hh
H = Healthy
h = PKU
hh
H?
H?
1) Manny and Rosa are married and both are healthy.
2) They have 3 children.
3) Their oldest child, Jacob, has a recessive disorder
called PKU.
4) Their middle child Erica and their youngest Matthew
are healthy.
• If healthy is dominant to PKU, fill in the missing
genotypes. (start with what you know)
The Next Generation
Key
H = Healthy
Hh
Hh
h = PKU
H?
hh
5) Erica meets Moe at college and the two become
married.
6) Erica and Moe have 2 daughters.
7) Their youngest daughter Jamie shows signs of PKU
while Amy does not.
• Fill in the genotypes of the four individuals. (start with
what you know)
Pedigrees contd.
• How that that example is finished, there is
another family on the next slide. This
family has a history of sickle cell disease
in their family.
• Try and fill in the genotypes of every
person in this family.
Sickle cell anemia (recessive) pedigree
Hint: 3 unknown
hh
hh
hh
Start with the
shaded circles
and squares.
They must be
hh because
they have the
disease.
Key
H = Healthy
h = Sickle cell disease
Sickle cell anemia (recessive) pedigree
Hint: 3 unknown
H
H
H
hh
hh
H
H
H
hh
Everyone else
is healthy so
they have at
least one
capital H.
H
H
hh
Key
H = Healthy
H
h = Sickle cell disease
Sickle cell anemia (recessive) pedigree
Hint: 3 unknown
H
H
Hh
hh
hh
H
H
H
H
hh
George must be
Hh because he
fathered Wilma
and Tom. If he
was HH, none
of his kids
would have the
disease.
H
H
hh
Key
H = Healthy
h = Sickle cell disease
Sickle cell anemia (recessive) pedigree
Hint: 3 unknown
H
H
Hh
hh
hh
Hh
H
H
H
hh
Sam and Ann
must be Hh
because Arlene
is their mother.
Arlene (hh)
must pass h to
each child she
has.
Hh
H
hh
Key
H = Healthy
h = Sickle cell disease
Sickle cell anemia (recessive) pedigree
Hint: 3 unknown
H
H
Hh
hh
hh
Hh
H
H
H
hh
Michael must
be Hh because
Carla has the
disease. If
Michael was
HH, then Carla
would not have
the disease.
Hh
Hh
hh
Key
H = Healthy
h = Sickle cell disease
Sickle cell anemia (recessive) pedigree
Hint: 3 unknown
H
Hh
Hh
hh
hh
Hh
Hh
H
hh
Daniel and Alan
must be Hh
because their
father (Tom)
passed h to
each of them.
Hh
Hh
hh
Key
H = Healthy
H
h = Sickle cell disease
Sickle cell anemia (recessive) pedigree
Hint: 3 unknown
H?
Hh
Hh
hh
hh
Hh
Hh
H?
H?
hh
Sandra, Tina,
and Christopher
are unknown.
They are either
HH or Hh. We
cannot tell from
this limited
information.
Hh
Hh
hh
Key
H = Healthy
h = Sickle cell disease
Review
1) Which symbols show
males? Females?
2) What does it mean if
persons 1, 10, and 12 are
colored black?
3) How are persons 1 and 8
related to each other?
4) Which two people are not
genetically related to this
family?