Name Date Blck Chapter 11 Human Genetic Disrders CP Bilgy 1. Majr types f genetic disrders: 2. Autsmal genetic disrders are caused by Mst are (need 2 recessive alleles t have the disrder) Peple with 1 recessive allele are - they d NOT have the disrder but are able t Ex: cystic fibrsis (CF), sickle-cell anemia Can als be (need nly 1 allele t have the disrder) Ex: Huntingtn s disease A) Cystic Fibrsis CF is the mst cmmn genetic disrder amng ~1 in 2500 white infants in the US are brn with CF (4-5 brn each day) It is estimated that 1 in 20 white peple is a carrier f the CF allele Caused by an abnrmal gene n The gene is fr a that uses t regulate the mvement f sdium (Na+) and chlride (Cl-) ins int and ut f cells In healthy individuals, the nrmal prtein With CF, nt enugh Cl- ins are pumped ut f cells Keeps mucus thin and in airways & pancreatic ducts Symptms f CF: Buildup f mucus in Difficulty Blcks (prduced by the pancreas) frm entering the intestine Abnrmal Na+ transprt als results in
Treatments fr CF: Fr respiratry symptms: in severe cases Fr digestive symptms: Capsules cntaining B) Sickle-Cell Anemia ( ) The mst cmmn genetic disrder amng Abut 1 in 500 African Americans has sickle-cell anemia. Carriers are said t have sickle-cell Caused by an abnrmal gene n The gene is fr ne f the plypeptide chains in, a prtein fund in that is respnsible fr Sickle-cell anemia causes hemglbin t within red bld cells, frm the nrmal bicncave disc t a sickle shape. Peple with sickle-cell trait have sme but d nt have the symptms f sickle-cell disease Symptms f Sickle-Cell Anemia: Abnrmal hemglbin as efficiently t cells as in healthy individuals Sickled red bld cells cannt mve as easily thrugh as nrmal RBCs Chrnic, especially in t infectins Treatments fr Sickle-Cell Anemia: that increase the xygen-carrying capacity f red bld cells Drugs that switch n the gene fr hemglbin (nrmally switched ff after birth)
Heterzygte Superirity Sickle-cell anemia is mst cmmn in areas f the wrld where is prevalent Malaria is caused by a parasite that These parasites d nt thrive in peple with, s peple with sickle-cell trait are t malaria Peple wh are heterzygus fr the cystic fibrsis allele may be mre resistant t When have an advantage ver peple wh are, it is called C) Huntingtn s Disease Caused by an (unlike mst human genetic disrders) Bth men & wmen t get the disrder Symptms f Huntingtn s disease Huntingtn s disease affects a persn s Lss f muscle crdinatin and ability t speak Symptms nrmally appear by Huntingtn s disease is always Death nrmally ccurs within after the nset f symptms 3. Many genetic disrders are believed t be the result f : (Type 1 & II) Biplar disrder, schizphrenia These are much mre cmplicated t analyze than disrders caused by single genes 4. Sex-linked disrders are almst always caused by mutant alleles n the Wmen can be, but men cannt Ex: Hmzygus nrmal female: X B X B Carrier female: X B X b Clrblind female: X b X b Nrmal male: X B Y Clrblind male: X b Y
A) Hemphilia is caused by an abnrmal gene fr Bld des nt clt nrmally, s even a tiny cut can result in is als a majr cncern Mst cmmn arund Hemphiliacs B) Red-green clrblindness is caused by an abnrmal gene fr The genes fr bth red and green phtreceptrs are lcated n the X chrmsme clrblindness can result frm recessive alleles fr either ne r bth f these genes 5. Chrmsme abnrmalities are caused by mistakes made during meisis May change the r f chrmsmes in the gametes that are frmed - the failure f a pair f chrmsmes t separate during meisis Results in ne gamete having t many chrmsmes and anther t few - a zygte gets 3 cpies f a chrmsme - a zygte gets nly 1 cpy f a chrmsme is when a piece f ne chrmsme breaks ff and attaches t a different chrmsme Often happens t 2 chrmsmes at nce Bth nndisjunctin and translcatin can be detected in Made frm taking individual pictures f all f a human s chrmsmes and matching up A) Dwn syndrme a genetic disrder that results frm chrmsme abnrmality Nndisjunctin the persn has an extra cpy f Translcatin mst f chrmsme 21 breaks ff during meisis and fuses with anther chrmsme Symptms f Dwn syndrme: Mild t severe Susceptibility t and
Sectin 2 1. disabilities are different frm genetic disrders Occur during 2. Bth genetic and cngenital disrders can ften be detected 3. Genetic Can help parents determine the f their child being brn with a genetic disrder Genetic cunselrs study the f bth parents Create t trace the passage f traits analyze bld tests t determine if parents are f certain genetic disrders Usually can NOT determine whether r nt a child will be brn with a disrder, nly the prbability 4. Tw main ways t diagnse genetic disrders: Analysis f techniques: A) Amnicentesis is the fluid that surrunds a fetus inside the uterus Als cntains fetal cells A sample f amnitic fluid is taken and cells are grwn in a lab Can be used t make a Detects Can be analyzed fr Detects Cannt be cnducted until
B) Chrinic Villus Bipsy Chrinic villi are structures that help maximize the surface area fr between a mther and develping fetus (they are part f the ) The villi develp frm and therefre cntain the same as the fetus & amnitic fluid A sample f these cells can be taken and analyzed as in amnicentesis Can be dne as early as C) Ultrasngraphy Uses high-frequency which bunce ff f tissue Depending n the f the tissue, the waves ech back at different and are used t prduce a cmputerized image called an Used in mst pregnancies t detect Used with amnicentesis t Can als help dctrs detect abnrmalities such as D) Fetscpy A is made in a pregnant wman s An is inserted thrugh the incisin Has a n the end that n a mnitr can be inserted thrugh the endscpe tube t 5. Develping cures fr genetic disrders: A) Gene therapy Intrducing int the cells f peple with Using Enclsing alleles in, which are taken int the cell by Currently these are still and have had