HEMOPHILIA

Anthony TriplinSteve Jean

Jude Saint-Jean

February 1, 2010

Period:3

Hemophilia

Blood does not clot as quickly Most common in males Also known as Christmas disease Double vision, repeated vomiting, extreme

fatigue Only males get type A and B Females get type C Type C less common

Location of Hemophilia

Located on X chromosome

Mode of Inheritance

Hemophilia is sex linked/ x-linked Can only be passed down on X chromosome Hemophilia A ( 1 in 10,000 male births, 1 in

100,000,000 female births)

Alleles Two alleles for each gene Half from your mom and half from your dad A capital letter for dominant allele and a lower-case

letter for the recessive allele Dominant allele takes over a recessive allele Recessive produces only when its paired allele is

identical A X-linked dominant chromosome is represented as XH

A X-linked recessive chromosome is represented as Xh

Hemophilia Punnett Squares

XH Y

XH

Xh

XHXH XHY

XHXh XhY

•Punnett squares are used to show the probability of receiving a genetic disorder from a parent.

YXh

XH

XH

XHXh XHY

XHXh XHY

Xh Y

XH

Xh

XHXh XHY

XhXh XhY

Male w/ hemophilia and female non-carrier Male w/ hemophilia and female carrier

Homozygous Dominant

Heterozygous Dominant Homozygous

Recessive

Normal Male and female carrier

Punnett Square Probability

Ratios:1 : 1 : 1 : 1

1 XHXH : 1 XHXh : 1 XHY : 1 XhY

Percentages:

25% : 25% : 25% : 25%

25%XHXH : 25% XHXh : 25% XHY : 25%XhY Normal Male and female carrier

XH Y

XH

Xh

XHXH XHY

XHXh XhY

Punnett Squares Genotypes and Phenotypes

What do the letters mean ?•Uppercase letters represent dominant genes•Lowercase letters represent recessive genes•H is the dominant allele •h is are the recessive allele

Phenotype/What We SeeXHXH = Non CarrierXHXh = CarrierXHY= NormalXhY= Hemophilia

Genotype/What Is In Our GenesXHXH is the Homozygous dominantXHXh is the Heterozygous dominantXhY is the Homozygous recessive

Normal Male and female carrier

XH Y

XH

Xh

XHXH XHY

XHXh XhY

Genotype/Phenotype Probability

•Phenotype= The observable characteristic of an organism (Expression of genes)

-Ratios- 1 XHXH: 1 XHXh: 1 XHY: 1XhY- Percentages- 25% With Hemophilia

75% Without Hemophilia

•Genotype- The specific Allele makeup of an organism

- Ratios- 1 XHXH: 1 XHXh: 1 XHY: 1XhY- Percentages- 25%XHXH: 25% XHXh: 25% XHY: 25%XhY

Punnett square of a Normal Male and a Carrier Female

XH Y

XH

Xh

XHXH XHY

XHXh XhY

Student PracticeNow you try!

Genotype:Ratio: 2 XHXh : 2 XHY

Percentage: 50% Hemophilia Carrier 50% Normal

Phenotype:Ratio: 2 XHXh : 2 XHY

Percentage: 50% HY 50% hY

XH

Xh

XHXh

XHXh

XHY

For example: Eye color

Y

XH XHY

THREE GENERATION X-LINKED PEDIGREE CHART

White= Person is fine. May of two “healthy genes.”Black= Person is affected. Has 2 “bad” genes.

How to read:

Circle= FemaleSquare= Male

Shaded Circle= Female Hemophilia CarrierShaded Square= Male hemophiliac

Student Practice:

How to read an X- Linked Pedigree Chart.

Key: Square= MaleCircle= Female

Red Square= Male hemophiliacYellow Circle= Female carrier

Joe Jan

Marc Cindy Dan

Tom Jr.Lisa

You think you know X- linked Pedigree’s? If so:1. Who is the main source of the hemophilia in this family?2. How many people in this chart DO NOT have any form of

hemophilia?3. If Marc were to have children with a normal female, what

are the odds of one of them having some form of hemophilia?

TomKayla