Genetic Disorders

I. Causes of Genetic Disorders A. Mutations: A change in the __________ sequence leads to a different _______.

I. Causes of Genetic Disorders A. Mutations: A change in the nucleotide sequence leads to a different protein.

B. Chromosomal Abnormalities: Abnormal ______ of chromosomes.

B. Chromosomal Abnormalities: Abnormal number of chromosomes.

II. Disorders Caused by Mutations

Condition/DisorderPattern of Inheritance 1.PKU (Phenylketonuria)Autosomal recessive (not sex-linked) rr = PKU Physical Effects Lack an enzyme to break down the amino acid _____________.

Condition/DisorderPattern of Inheritance 1.PKU (Phenylketonuria)Autosomal recessive (not sex-linked) rr = PKU Physical Effects Lack an enzyme to break down the amino acid phenylalanine.

Condition/DisorderPattern of Inheritance 1.PKU (Phenylketonuria)Autosomal recessive (not sex-linked) rr = PKU Physical Effects Lack an enzyme to break down the amino acid phenylalanine. Can lead to mental impairment & death. Treatment: _______________ ______________________________________________________

Condition/DisorderPattern of Inheritance 1.PKU (Phenylketonuria)Autosomal recessive (not sex-linked) rr = PKU Physical Effects Lack an enzyme to break down the amino acid phenylalanine. Can lead to mental impairment & death. Treatment: Have “Phe” levels tested/regulate the amount of protein the patient consumes that contains phenylalanine.

Condition/DisorderPattern of Inheritance 2. Sickle Cell AnemiaCodominant (H A = Normal hemoglobin) (H S = Abnormal hemoglobin/Sickled Cells) Physical Effects Red blood cells are shriveled or _______. Cannot carry as much ______ for the body.

Condition/DisorderPattern of Inheritance 2. Sickle Cell AnemiaCodominant (H A = Normal hemoglobin) (H S = Abnormal hemoglobin/Sickled Cells) Physical Effects Red blood cells are shriveled or sickled. Cannot carry as much oxygen for the body.

Condition/DisorderPattern of Inheritance 2. Sickle Cell AnemiaCodominant (H A = Normal hemoglobin) (H S = Abnormal hemoglobin/Sickled Cells) Physical Effects Red blood cells are shriveled or sickled. Cannot carry as much oxygen for the body. Shriveling of cells is due to an amino acid substitution which results in abnormal __________ structure.

Condition/DisorderPattern of Inheritance 2. Sickle Cell AnemiaCodominant (H A = Normal hemoglobin) (H S = Abnormal hemoglobin/Sickled Cells) Physical Effects Red blood cells are shriveled or sickled. Cannot carry as much oxygen for the body. Shriveling of cells is due to an amino acid substitution which results in abnormal hemoglobin structure. **When cells sickle, they block blood flow (pain/low oxygen to organs)

Condition/Disorder 2. Sickle Cell Anemia **Common in people of _______ descent.

Condition/Disorder 2. Sickle Cell Anemia **Common in people of African descent.

Condition/Disorder 2. Sickle Cell Anemia **Common in people of African descent. Why? H A H A = 100% normal RBCs H A H S = 50% normal RBCs (normal health) H S H S = 100% abnormal RBCs (Sickle-cell disease)

Condition/Disorder 2. Sickle Cell Anemia **Common in people of African descent. Why? H A H A = 100% normal RBCs H A H S = 50% normal RBCs (normal health) H S H S = 100% abnormal RBCs (Sickle-cell disease) **Resistant to Malaria (Malaria bug lives out part of its life cycle in RBCs)

Condition/Disorder 2. Sickle Cell Anemia **Common in people of African descent. Why? H A H A = 100% normal RBCs – many died from malaria H A H S = 50% normal RBCs (normal health) - H S H S = 100% abnormal RBCs (Sickle-cell disease) – died from Sickle Cell Disease

Condition/Disorder 2. Sickle Cell Anemia **Common in people of African descent. Why? H A H A = 100% normal RBCs – many died from malaria H A H S = 50% normal RBCs (normal health) – Survived to pass on genes H S H S = 100% abnormal RBCs (Sickle-cell disease) – died from Sickle Cell Disease

Condition/DisorderPattern of Inheritance 3. Tay-Sachs DiseaseAutosomal Recessive **Jewish bloodlinesrr = Tay-Sachs Disease Physical Effects Results in defective lysosome ______.

Condition/DisorderPattern of Inheritance 3. Tay-Sachs DiseaseAutosomal Recessive **Jewish bloodlinesrr = Tay-Sachs Disease Physical Effects Results in defective lysosome enzyme. This enzyme breaks down a type of brain fat (ganglioside) which can literally poison the brain. Mental impairment, blindness, deafness, loss of swallowing ability, & death by age 4.

Condition/DisorderPattern of Inheritance 4. Huntington’s DiseaseAutosomal Dominant RR/Rr = Disease Physical Effects Physical effects show up between the ages of __ and __. Results in mental illness, severe loss of memory, loss of motor skills. Caused by a dysfunctional enzyme that leads to brain damage.

Condition/DisorderPattern of Inheritance 4. Huntington’s DiseaseAutosomal Dominant RR/Rr = Disease Physical Effects Physical effects show up between the ages of 30 and 50. Results in mental illness, severe loss of memory, loss of motor skills. Caused by a dysfunctional enzyme that leads to brain damage. (Mutation in a single gene)

A Few Others…… Cystic Fibrosis : Autosomal Recessive – Abnormal protein (thick/mucousy) builds in lungs & blocks pancreatic duct.

Icthyosis (Scaly Skin)

Albinism

Dwarfism (autosomal dominant) Rr = dwarfism; rr = normal

III. Chromosomal Abnormalities - These are not inherited disorders. They are “flukes” that result from a _______________ of sister chromatids during Anaphase II of Meioisis.

III. Chromosomal Abnormalities - These are not inherited disorders. They are “flukes” that result from a non-disjunction of sister chromatids during Anaphase II of Meioisis.

1. Down Syndrome (AKA Trisomy 21) Total number of chromosomes: __

1.Down Syndrome (AKA Trisomy 21) Total number of chromosomes: 47 Eggs Chromosome 21 Sperm:

1.Down Syndrome (AKA Trisomy 21) Total number of chromosomes: 47 Eggs Chromosome 21 Sperm: Baby: Trisomy 21??

1.Down Syndrome (AKA Trisomy 21) Total number of chromosomes: 47 Eggs *1/800 – 1000 children *1/2500 – Young Mothers *1/350 (Age 35); 1/25 (Age 45) Chromosome 21 Sperm: Baby: Trisomy 21??

Small headMental Impairment Low muscle tone Single crease in handStubby limbs Small, abnormal ears Upward slant to eyesFlat nasal bridge Heart defects Digestive problemsEnlarged tongue Visual problems

2. Turner’s Syndrome (__). Total number of chromosomes: __.

2. Turner’s Syndrome (XO). Total number of chromosomes: __.

2. Turner’s Syndrome (XO). Total number of chromosomes: 45. XX

2. Turner’s Syndrome (XO). Total number of chromosomes: 45. XX XX

2. Turner’s Syndrome (XO). Total number of chromosomes: 45. XX XX XYXXYY

2. Turner’s Syndrome (XO). Total number of chromosomes: 45. XX XX XYXXYY

FemaleSmall lower jaw Webbed neckHearing loss Short statureBroad chest Heart defectPuffy hands/feet Kidney abnormalitiesNo development during puberty Low hairlineSterile (possibly)

3. Klinefelter’s Syndrome (__). Total number of chromosomes: __

3. Klinefelter’s Syndrome (XXY). Total number of chromosomes: __

3. Klinefelter’s Syndrome (XXY). Total number of chromosomes: 47

XX XX XYXXYY

3. Klinefelter’s Syndrome (XXY). Total number of chromosomes: 47 XX XX XYXXYY

Male(severe acne)Social Maladjustment Sterile50% are dyslexic Slight Breast developmentSpeech problems Low muscle tone2.5 inches above average height Sparse body hairDon’t produce enough testosterone

XYY – “Super Male Syndrome”

Tall Severe acne Violent Low IQ

Progeria