TAY-SACHS DISEASE GENETIC DISORDERS MIGUEL URBINO & JAZZ RANDALL PERIOD 3

OTHER PEOPLE MAY HAVE THIS DISEASE AND BE RESPECTFUL WHEN REACTING PLEASE KEEP IN MIND

SUMMARY Very rare This disorder is inherited It destroys the nerve cells in your brain and spinal cord Recessive gene Mostly occurs in infants Survival rate is up to 3 to 4 years of age

INFANTS Lose their motor skill ability such as turning over, sitting, and crawling Exaggerated startled reactions to loud noises Not easily noticed at first Go through seizures, vision and hearing loss, intellectual disability, and paralysis

CHROMOSOME 15 The HEXA- Chromosome 15 Tay Sachs is caused by mutations in the HEXA gene

MODE OF INHERITANCE  How would one acquire Tay Sachs? -if the parents of an offspring are both a carrier of the disease then you get full Tay Sachs  What does sex linked/x-linked, autosomal recessive or autosomal dominant mean? - If a disease is autosomal dominant, it means you only need to get the gene from one parent in order for you to inherit the disease. - An autosomal recessive disorder means two copies of the gene must be shown in order for you to inherit the disease or trait. - Sex-linked means that a single gene on the X chromosome can cause the disease. This can happen in boys and girls but in the case of males they may not survive.

ALLELES An allele is an alternative form of a gene that is located at a specific position on a specific chromosome 2/per gene They come from our parents whether they carry the trait or not Recessive= r Dominate= R Dominant means you are more likely to inherit something from your parents Recessive means you can inherit it from your parents but it is a less likelihood you will

PUNNETT SQUARES FATHER'S GENES Tt MOTHER'STTTTt GENEStTttt FATHER'S GENES TT MOTHER'STTT GENEStTt FATHER'S GENES TT MOTHER'STTT GENESTTT FATHER'S GENES tt MOTHER'STTt GENESttt

Ratios: 1:2:1 1TT: 2Tt: 1t FATHER'S GENES Tt MOTHER'STTTTt GENEStTttt ANALYZING PUNNETT SQUARES Percentages: 25%:50%:25% 25%TT: 50%Tt: 25%t

ANALYZING PUNNETT SQUARES (CONTINUED) What do the letters mean? FATHER'S GENES Tt MOTHER'STTTTt GENEStTttt Phenotype: (Physical Color) TT= Red Tt = Yellow tt = Green Genotype: TT = Homozygous Dominant Tt = Heterozygous Dominant tt = homozygous recessive

ANALYZING PUNNETT SQUARES (CONTINUED) Genotype and Phenotype FATHER'S GENES Tt MOTHER'STTTTt GENEStTttt Phenotype: (Physical Color) Ratios- 1 Red : 2 Yellow : 1 Green Percentages- 25% Red : 50% Yellow : 25% Green Genotype: Ratios- 1 TT : 2 Tt : 1 tt Percentages- 25% TT : 50% Tt : 25% tt

PHENOTYPE: Ratio- Percentages- FATHER'S GENES tT MOTHER'St GENEST PRACTICE PUNNETT PROBLEMS GENOTYPE: Ratio- Percentages-

3 GENERATION HYPOTHETICAL PEDIGREE LEGEND: Square = Male Circle = Female Red = TT Yellow = Tt Green = tt

PEDIGREE PRACTICE LEGEND: Square = Circle = Shaded = Half Shaded = Not Shaded = ANALYZING PEDIGREES Read the Questions CAREFULLY 1.Is it possible for a TT and Tt to have a tt off-spring? 2.Is it possible for a Tt and Tt to have a TT off-spring? 3.Is it possible for a tt and TT to have a TT off-spring?

THANK YOU FOR YOUR ATTENTION AND COOPERATION MIGUEL URBINO & JAZZ RANDALL PERIOD 3