Presentation on theme: "HUMAN GENETICS Disorders. How information is taken to detect genetic disorders before birth zBlood test zAmniocentesis zChorionic villus sampling CVS."— Presentation transcript:
HUMAN GENETICS Disorders
How information is taken to detect genetic disorders before birth zBlood test zAmniocentesis zChorionic villus sampling CVS zUltrasound imaging
Blood Test zSuch as PKU –check if baby does not have enzyme to break down PKU
Amniocentesis zsmall amount of amniotic fluid, which contains fetal tissues, is sampled and the fetal DNA is examined for genetic abnormalities.
CVS chorionic villus sampling zSample of the placenta to test for genetic abnormalities
Ultrasound imaging zvisualizing internal body structures including tendons, muscles, joints, vessels and internal organs for possible pathology or lesions zEX: good for Achondroplasia (short limbs)
PKU on chromosome 12 Lacks the enzyme to break down the amino acid phenylalanine (found in milk)
PKU (cont.) zThe breakdown products can be harmful to developing nervous systems zLeads to mental retardation. zKate with PKU MovieKate with PKU Movie Julie has PKU; been treated all her life KUVAN®
PKU zChromosome 12 zrecessive zPut on low protein diet zAvoid phenylalanine
TAY SACHS zResults in degeneration of the nervous system. zChromosome 15 zrecessive zHighest rate in Eastern European Jews
Tay Sachs (cont) zLack enzyme to break down fat, accumulates in brain ztt zChromosome 15 zTay Sachs YouTubeTay Sachs YouTube zNOVA Online | Cracking the Code of Life | Watch the Program Here #3NOVA Online | Cracking the Code of Life | Watch the Program Here
Tay-Sachs Symptoms Symptoms first appear at 4 to 6 months of age when an apparently healthy baby gradually stops smiling, crawling or turning over, loses its ability to grasp or reach out, and eventually becomes blind, paralyzed and unaware of its surroundings. Death occurs by age 4.
Albinism zInability to manufacture pigments (melanin) in skin and eyes zAutosomal recessive trait zChromosome 11 z(will be in movie)
zAndy Warhol, a famous musician and filmaker (now dead), was an albino. Rock musician Edgar Winter, an albino.
zDifferent kinds of albinism affect chromosomes 1, 9, 10, 11, 15 and X. Often rapid back and forth eye movement – lack of pigment in eyes.
Albinism VideoAlbinism Video (8:35)
Sickle Cell Anemia zAutosomal dominant disease #11 zRed blood cells collapse and clot blood vessels zFound in African- Americans
Sickle-Cells zNormal Red Blood Cells-like a donut zSickle-cells collapse, hard, clog vessels
Sickle-Cell Anemia zCodominant zSS = disease zAS = carrier (somewhat resistant to malaria) zAA =normal hemoglobin zSickle Cell Disease - What Causes Sickle Cell Disease Video - About.comSickle Cell Disease - What Causes Sickle Cell Disease Video - About.com
Pleiotropy zAlleles responsible for multiple symptoms zEX: sickle-cell anemia – low oxygen in blood, resistance to malaria, spleen damage, joint problems Plasmodium in blood
Sickle-Cell Complications 1.pain episodes 2.strokes 3.increased infections 4.leg ulcers 5.bone damage 6.yellow eyes or jaundice 7.early gallstones 8.lung blockage 9.kidney damage and loss of body water in urine 10.painful erections in men (priapism) 11.blood blockage in the spleen or liver (sequestration) 12.eye damage 13.low red blood cell counts (anemia) 14.delayed growth
Huntington’s Disease zWoody Guthrie’s disease (folksinger 1960’s) zAutosomal dominant zDoes not manifest itself until age 20’s - 30’s zH=dominant disease
Familial (genetic) Hypercholesterolemia zAutosomal dominant-H zExcess cholesterol in the blood zChromosome 19
Most common is mutation in LDLR low-density lipoprotein receptor (bad cholesterol ) FH YouTube (good) 1:53FH YouTube
Huntington’s zChromosome 4 zAutosomal dominant zAtrophy of brain zUncontrollable muscle spasms zHuntington's Disease Information - HOPES - HOPES Video Player (SWF)Huntington's Disease Information - HOPES - HOPES Video Player (SWF) z(segment 4) zNew Treatment for Huntington's Disease - Health Videos – redOrbitNew Treatment for Huntington's Disease - Health Videos – redOrbit z40+ CAG’s zHowStuffWorks Videos "Treating Huntington's Disease"HowStuffWorks Videos "Treating Huntington's Disease"
Huntington’s zClumsiness zJaw clenching zLoss of coordination and balance zSlurred speech zSwallowing and/or eating difficulty zUncontrolled continual muscular contractions zWalking difficulty, stumbling zHostility/irritability Inability to take pleasure in life zLack of energy zperson with Huntington's also may exhibit psychotic behavior: zDelusion zHalluciations zInappropriate behavior (e.g., unprovoked aggression) zParanoia
Alzheimer Syndrome zAutosomal Dominant zFound on Chromosome 1, or 10, or 14, or 19, or 21 zAPO4, is a cholesterol- carrying protein linked to development a protein that forms plaque in the brain
Brain Loss Alzheimers Disease -3D animation You Tube (1 min) Inside the Brain: Unraveling the Mystery of Alzheimer's Disease [HQ] (4:22) Alzheimers Disease -3D animation You Tube Inside the Brain: Unraveling the Mystery of Alzheimer's Disease [HQ]
Early or mild stage: What is Alzheimer's? YouTube (3:15) What is Alzheimer's? YouTube zmemory loss, especially of recent events zdifficulty in recalling names and conversations zmisplacing objects zbecoming lost in familiar neighborhoods zrepeating stories and conversations zdifficulty in learning new information zpersonality changes zdecreased motivation and drive zeasily upset or anxious
Marfan Syndrome zautosomal dominant disorder z chromosome 15 z(will be in movie)
Marfan’s: taller, pigeon chest Spidery fingers, enlargement of aorta
Marfan Syndrome Marfan Syndrome You Tube (2:45) Marfan Syndrome You Tube za connective tissue disorder, zAffects skeleton, lungs, eyes, heart and blood vessels. zunusually long limbs zaffected Abraham Lincoln.
Hemophilia passed by queen victoria zBlood does not clot normally zSex-linked recessive zMissing AHF (clotting factor in blood) zCzar Nicholas royal family
Royal Pedigree- Hemophilia
“bleeder’s disease” zX H X h = female carrier zX h X h = female hemo zHemophilia Video (from WHF)Hemophilia Video zYoung Boy hemophilia treatment You TubeYoung Boy hemophilia treatment You Tube zX H Y = normal male zX h Y = hemo male
Color Blindness zinability to perceive differences between some of the colors that others can distinguish. zMore common in males zSex-linked (red and Green) on X chromosome recessive z
Color Blindness z3 seconds to determine number Ishihara Test for Color Blindness
zThe individual with normal color vision will see a 5 revealed in the dot pattern. An individual with Red/Green (the most common) color blindness will see a 2 revealed in the dots.
Color blindness=can’t tell certain colors zRecessive on X chromosome = c zX C X c = normal female (carrier) zX c Y = color-blind male
What numbers do you see?
Note: X and Y used
Need X and Y on Punnetts
Duchenne Muscular Dystrophy
DMD zDuchenne Muscular Dystrophy zOn X m chromosome zWeakens and degenerates muscles zFound mostly in males z#1 fatal disease to affect boys Guillaume- Benjamin Duchenne de Boulogne
DMD zabsence of dystrophin, a protein that helps keep muscle cells intact Leg muscles first. Calves often enlarged.
DMD zOnset ·Early childhood - about 2 to 6 years. z Symptoms · Generalized weakness of muscle zWasting affecting limb and trunk DMD Timeline YouTube DMD Timeline YouTube (good one) (5:43)
DMD zSurvival rare beyond late twenties. zX-linked recessive (females are carriers ).
POLYGENIC DISORDERS zDetermination of disorder occurs on more than one chromosome
SPINA BIFIDA is a fault in the spinal column in which one or more vertebrae (the bones which form the backbone) fail to form properly, leaving a gap or split.
Spina Bifida (POLYGENIC) #6, #14 and others zGap in spinal column zSpinal Bifida Genetics You Tube (1:53)Spinal Bifida Genetics You Tube
Shunts often put in the brain to drain the fluid Spinal Bifida Facts Video You Tube (4:38) Spinal Bifida Facts Video You Tube
Agent Orange zChildren with Spina Bifida whose parent was in contact with Agent Orange during the Vietnam War are compensated
Cleft Lip/Cleft Palate zA cleft is an opening in the lip, the roof of the mouth (hard palate) or the soft tissue in the back of the mouth (soft palate). #11, #17, #22
Clefts Clefts occur more often among Asians and certain groups of American Indians than among whites. They occur less frequently among blacks.
Cleft lip/palate zAs you can imagine there are feeding problems z#11, #22, #17 – zPolygenic zCleft Lip and Palate You Tube (5;04)Cleft Lip and Palate You Tube
On Y chromosome zTestes determining factor
SRY gene zA sex-determining gene on the Y chromosome z(Sex-determining region Y)
NOTE: zIf you are born with no “X” chromosome- it is fatal zIf missing an autosome-it is fatal
X chromosome zSex-linked traits
Triple-X Syndrome ztriplo-X ztrisomy X zXXX syndrome z47,XXX aneuploidy There is usually no distinguishable difference to the naked eye between women with triple X and the rest of the female population.
Triple-X Syndrome zAlthough females with this condition may be taller than average, this chromosomal change typically causes no unusual physical features. zMost females with triple X syndrome have normal sexual development and are able to conceive children.
Nondisjunction zChromosomes to segregate unevenly during meiosis zMistakes in MeiosisMistakes in Meiosis
Turner’s Syndrome Adults with Turner syndrome are short, averaging around four feet, eight inches in height. Flap in neck Small breasts
zBut girls with Turner syndrome don't start life as very short individuals - they become short over time-do not develop sexually
Turner’s Syndrome 45 X0
Kleinfelter’s 47 XXY
Kleinfelter’s -Testes are small -breast growth (gynaecomastia) -poorly developed secondary sexual characteristics.
Klinefelter’s zMen are sterile (no sperm).
Special Topics In Human Genetics
BARR BODIES zWhen a female is born one of her X chromosomes is inactivated = a Barr Body (early in embryonic development) zUsed to test femaledness at Olympics zSo there is not excess of X info in females
Calico Cat – X linked zOnly females have 3 colors (orange, black, white) zLooks like “Pepper”
Multiple colors in cats mostly in females
zGENETIC DISORDERS REFERENCE SHEET: Down Syndrome (Trisomy 21) Edward's Syndrome (Trisomy 18) Patau Syndrome (Trisomy 13) Klinefelter Syndrome (47, XXY) Turner Syndrome (45 XO) Metafemale (46XXX)-taller Autosomes (#1-22) so 44 if normal