H EMOPHILIA Matt Carmen Josue Kernizan Matt Brill January 28 th, 2010 Period 6/7

S UMMARY OF H EMOPHILIA Hemophilia is a disorder of your blood-clotting system Clotting- the process by which your blood changes from a liquid to a solid state this is used to stop bleeding Painful, lasting headache Repeated vomiting Extreme fatigue Neck pain Double vision Nosebleeds with no obvious cause Tightness in your joints

W HAT CHROMOSOME HEMOPHILIA IS LOCATED ON ? The gene that causes hemophilia A or B is located on the X chromosome

Mode of Inheritance Acquired when a clotting gene is mutated, located in the x- chromosome. Caused by autosomal recessive genes- the disease travels via the autosomes. Hemophilia is an autosomal recessive disorder. Only men can get hemophilia A and B, because women have 2 x-chromosomes, so men, with an X and a Y recessive chromosome, can only contract this disorder. Hemophilia C occurs when two reccisive X chromosomes are combined.

A LLELES An individual inherits two alleles for each gene, one from each parent. Recessive is a quality found in the relationship between two versions of a gene. If the alleles are different, the dominant allele will be expressed, while the effect of the other allele, called recessive, is masked. RR=Dominant rr=recessive Rr=dominant There are many more X-linked traits than there are Y-linked traits.

XHXH XhXh XHXH Y XHXHXHXH XHYXHY XHXhXHXh XhYXhY A P HENOMINAL EXAMPLE OF A P UNNET S QUARE. XhXh XHXH XHXH XhXh XHXHXHXH XHXhXHXh XhXHXhXH XhXhXhXh

Ratios and Percents of Hemophelia Ratios- homozygous dominant : heterozygous dominant : homozygous recessive 1 : 2 : 1 1 X H X H : 2 X H X h : 1 X h X h Percentages- homozygous dominant : heterozygous dominant : homozygous recessive 25% : 50% : 25% 25% X H X H : 50% X H X h : 25% X h X h XhXh XHXH XHXH XhXh XHXHXHXH XHXhXHXh XHXhXHXh XhXhXhXh

What do these genes mean? The H genes, both dominant and recessive, are blood clotting genes. Phenotype: X H X H – blood clots X H X h - blood clots ( carrier) X h X h- blood doesn’t clot Genotypes: X H X H- Homozygous dominant (blood clots) X H X h – Heterozygous dominant (blood clots, carrier) X h X h – Homozygous recessive (blood doesn’t clot) XhXh XHXhXHXh XHXH XHXH XhXh XHXHXHXH XHXhXHXh XhXhXhXh

Probabilities of Geno/Phenotypes Phenotype Ratio- 3 blood clot: 1 non-blood clot Percent- 75% blood clot: 25% non-blood clot Genotype Ratio- 1 X H X H : 2 X H X h : 1 X h X h Percent- 25% X H X H : 50% X H X h : 25% X h X h XhXh XHXhXHXh XHXH XHXH XhXh XHXHXHXH XHXhXHXh XhXhXhXh

Student Practice Phenotype: Ratio: Percentage: Genotype: Ratio: Percentage: XHXH XHXH Y XhXh XHXHXHXH XHYXHY XHXhXHXh XhYXhY 3:1 75%:25% 1:2:1 25%:50%:25%

3 Generation Pedigree Hemophilic Male Female Carrier Normal Female Normal Male

Student Practice 1.What shape shows a hemophiliac 2.How many people in the third generation have hemophilia 3.What gender must the dark rectangles be? Hemophilic Male Female Carrier Normal Female Normal Male