Genetic disorders Caused by: ~ _________________________ ________________________ Or ~ _________________________ _________________________

Altered Chromosomes # can change due to _________________ __________________________________ # can change due to _________________ __________________________________ structure can change _______________ __________________________________ __________________________________ structure can change _______________ __________________________________ __________________________________ ( Remember: chromosomes are DNA wrapped around histones. When the DNA is altered the structure changes)

________ & _________ - Substance that can cause a mutation - Ex - -UV Light -X-Rays -Radiation -Viruses -Tobacco 1- _______________ Mutation- reproductive cells (sperm & egg) 2- __________ Mutation- body cells (types of Cancer)

Types of structural Mutations 1- ________________- piece of chromosome is lost (Cri-du-Chat or Prader- Willi Syndrome) 2- __________________ - piece breaks off & reattaches upside down 3- ___________________- piece breaks off and attaches to a different chromosome

4- ____________________- removal of a single DNA nucleotide (one nitrogen base is substituted with another) Example- ** Original - The fat cat ate the wee rat. ** Point Mutation - The fat hat ate the wee rat. Carcinogen- mutation that may cause cancer

Cri du Chat Syndrome: ___________ Characteristics - High pitched mewing cry as an infant - Slant of the eyes - Mental retardation - _________________ __________________ __________________

Prader –Willi Syndrome: _____________ Characteristics - Infants are weak- sucking reflex is poor & feeding is difficult - _______________________ ______________________ - Children become extremely obese - ______________________ - Short stature - Poor sexual development - Behavioral issues

Changes in the Chromosome Number

_______________________- chromosomes fail to separate during Meiosis; will cause a lack of a chromosomes or will give you an extra chromosome _______________________- chromosomes fail to separate during Meiosis; will cause a lack of a chromosomes or will give you an extra chromosome 2 Types 1- _______________- lack a chromosome _________________________________ - _______ chromosomes = XO -________________________ - webbed neck- short - swelling at wrists & ankles - ______________________________

-2. Trisomy - ___________________________ - ex: __________________(Trisomy 21)- males & females, decreased muscle tone, slanting eyes, small mouth with protruding tongue, mental retardation

Types of Nondisjunction Klinefelter’s Syndrome ( ______________________ )- _____________________, tall (long legs with short trunk), infertile, low IQ, enlarged breast tissue (a type of Trisomy)

Detecting Human Genetic Disorders Genetic screening- examine a person’s genetic make-up (Karyotype, Blood tests) 2 methods: 1- ____________________- amniotic fluid withdrawal 2- ____________________ (CVS)- take a sample of villi (_____________________ _____________________) **Both produce Karyotype**

Detecting Human Genetic Disorders Advantage of both: - Physicians can detect more than _________________________________ Advantage of both: - Physicians can detect more than _________________________________ Disadvantage of Amniocentesis: most conditions are incurable and the results ____________________________________ (abortion at this time is very difficult) Disadvantage of Amniocentesis: most conditions are incurable and the results ____________________________________ (abortion at this time is very difficult) Disadvantage of CVS: __________________ ________________________or miscarriage but it comes back b/4 1 st trimester is over Disadvantage of CVS: __________________ ________________________or miscarriage but it comes back b/4 1 st trimester is over

Genetic Traits & Disorders Genetic Disorder- disease or set of conditions that have a genetic basis. 1- Single Allele Trait- 1 allele controls the trait A) ____________________: A) ____________________: Ex: Huntington’s disease, Achondroplasia (dwarfism), Cataracts, Polydactyl) B) _____________________: Ex: albinism, cystic fibrosis, sickle cell anemia, PKU, Marfan

Genetic Traits & Disorders 2.- ______________________ 3 or more alleles of the same gene code for a single trait Ex- Blood Groups (A, B, O) 3- ______________________- traits that are controlled by many genes (Skin, Hair & Eye color, Height, Foot size) 4- ______________________- phenotype depends on gender and hormones (Baldness)

Genetic Traits & Disorders 5- __________________- found only one the X Chromosome Examples- Colorblindness, Fragile- X, Hemophilia, Muscular Dystrophy, Ichthyosis simplex (Scaly skin)

Heterozygous advantage Malaria and sickle cell anemia _______________ _______________