Genetic Disorders A Collage of Multiple Syndromes

Syndromes Covered: Chromosomal Disorders Down syndrome (Trisomy 21) Edward’s syndrome (Trisomy 18) Patau’s syndrome (Trisomy 13) Klinefelter’s syndrome (XXY) Turner syndrome (XO) Super female syndrome (XXX) Super male syndrome (XYY) Cri du Chat (deletion on #5) Fragile X (duplication on X)

Single Gene Disorders Sickle Cell Anemia Cystic Fibrosis Huntington’s Disease Autism (???)

…And, Sex Linked Traits Color Blindness Hemophilia

Chromosomal Disorders …are usually caused by an error in cell division Karyotype!

Down Syndrome=Trisomy 21 A young boy with Down syndrome members.aol.com/InitiativeDo wn/index.htmmembers.aol.com/InitiativeDo wn/index.htm

This is what a karyotype of a girl with downs syndrome would look like m/genome/ six.html

Some physical characteristics of individuals with DS…

Edward’s Syndrome=Trisomy 18 Dakota, a young boy with Edward’s syndrome net/ dakotaphotos.html

Mental retardation Undescended testicles in malesUndescended testiclesmales Prominent back portion of the head head Small head (microcephaly)microcephaly Low-set, malformed earsmalformed ears Abnormally small jaw (micrognathia)micrognathia Small mouth Cleft lip/Cleft palateCleft lipCleft palate Upturned nose Narrow eyelid folds (palpebral fissures)palpebral fissures Growth deficiency Feeding difficulties Breathing difficulties Developmental delays Characteristics of Edward’s Syndrome

A karyotype of a male with Edward’s syndrome 100/ch10.html

Patau’s Syndrome=Trisomy 13 Meet Nicholas Wright the very proud son of Mark and Jayne Wright of Hudson, Illinois USA Nicholas was born with Trisomy wright.htm

Characteristics of Patau’s Syndrome Most embryos with trisomy 13 do not survive gestation and are spontaneously aborted. Of those surviving to term gestation, approximately 82-85% do not survive past 1 month of age, and 85-90% do not survive past 1 year of age. Central Nervous System malformations (no forebrain development) long term neurological disability, feeding difficulty, and frequent pneumonia and other respiratory infections. pneumonia *There have been 5 cases reported in the medical history of patients living beyond 10 years of age

Klinefelter’s Syndrome (XXY) William John Durfee, a patient with Klinefelter’s syndrome tiger.towson.edu/~tmcco r1/durf.htm

Male w/Klinefelter’s Female w/ Turner

k-12.pisd.edu/currInst/science/Genetic/karyo-kline-xxy.htm

Turner Syndrome (XO) Karen, a patient with Turner Syndrome re_50273/ aboutturners.html

fig.cox.miami.edu/Faculty/Dana/25001_13.html

sp.uconn.edu/~bi107vc/sp03/terry/division.html

Super Female Syndrome (Trisomy X) Females with Trisomy X are healthy and cannot be distinguished from (XX) females excepts by karyotype (shown) du/biocourses/N100/image s/XXXFemale.gif

Super Male Syndrome (XYY Syndrome) This syndrome is not well characterized although males that have XYY tend to be slightly taller than average Studies have shown that a large number of men imprisoned are XYY

Other Genetic Disorders… Cri du Chat (Deletion on part of #5) Characteristics: “Cry of the cat," referring to the distinctive cry of children with this disorder Abnormal larynx development, which becomes normal within a few weeks of birth Low birth weight Respiratory problems Sometimes shortened lifespan…but usually normal life expectancy duchat.gif

Fragile X Syndrome: Duplication of a piece of the X Chromosome Most common form of mental retardation Hyperactivity Short attention span Negative response to touch Hand-flapping Hand-biting Poor eye contact Repetition of words/phrases Double jointed Large or prominent earsprominent ears Large testicles

Single Gene Traits Sickle Cell Anemia Inherited blood disorder (recessive) Mostly affects people of African ancestory 1 in 12 African Americans have it Affects hemoglobin (which carries oxygen in blood) and makes Red Blood Cells sticky Interesting correlation between sickle cell and increased resistance to malaria

Cystic Fibrosis Inherited chronic disease that affects lungs and digestive system Defective gene causes the body to produce unusually thick, sticky mucus

Huntington’s Disease Hereditary brain disorder that diminishes ability to walk, think, talk, and reason Onset usually between the ages of 30-45

Tay-Sachs Disease Lipid accumulation in brain cells; mental deficiency; blindness; death in early childhood

Autism 3 distinctive behaviors that characterize autism: -difficulties with social interaction -problems with verbal and nonverbal communication -repetitive behaviors or narrow, obsessive interests. These behaviors can range in impact from mild to disabling

Sex-Linked Traits …linked to the sex chromosomes Color Blindness Hemophilia Both are usually found in males only- why??

Half shaded=carrier; If III-2 and III-3 have a child (I know...weird), what are the odds of it getting the “disease”?