2 Causes of genetic disorders Genetic disorder is an abnormal condition that a person inherits through genes or chromosomes.Some genetic disorders are caused by mutations in the DNA of genes.Other disorders are caused by changes in the overall structure or number of chromosomes.
3 Cystic fibrosisGenetic disorder in which the body produces an abnormally thick mucus in the lungs and intestines.The thick mucus fills the lungs making it difficult to breathe.Caused by recessive allele on one chromosome.The recessive allele causes three bases to be removed from on DNA molecule (mutation)
4 Sickle-cell diseaseAffects hemoglobin, the protein in red blood cells that carries oxygen.When oxygen concentration is low, the red cells have an unusual sickle shape.These sickle shaped cells will clog blood vessels and cannot carry as much oxygen.The allele for sickle cell is codominant.A person with one sickle cell allele and one normal will have both types of hemoglobin.A person with two sickle cell alleles will have the disease.
5 HemophiliaGenetic disorder in which a persons blood clots very slowly or not at all.Danger of internal bleeding from small bumps and bruises is very high.Caused by a recessive allele on the X chromosome.Because it is a sex linked disorder it is more common in males than females
6 Down syndrome A persons cells have an extra copy of chromosome 21. Instead of a pair of chromosomes, they have three.Most often occurs when chromosomes fail to separate properly during meiosis.People with down syndrome have mental retardation, and heart defects are common (can be treated).
7 pedigreesOne important tool that geneticists use to trace the inheritance of traits in humans is a pedigree.Pedigree is a chart or family tree that tracks which members of a family have a particular trait.
8 pedigree Horizontal line represents a union. Vertical line with a bracket represents children from union
9 Managing genetic disorders Today, doctors use tools such as karyotypes to help diagnose genetic disorders. People with genetic disorders are helped through medical care, education, job training, and other methods.
10 karyotypesIs a picture of all the chromosomes in a cell. The chromosomes are arranged in pairs.Karyotype can reveal if a person has the right number of cells.Look at this karyotype, does this person have any disorders?
11 Genetic counselingGenetic counselors help couples understand their chances of having a child with a particular genetic disorder.They use tools such as; karyotypes, Punnett squares, pedigree charts to help in their work.
12 Dealing with genetic disorders Physical therapy helps remove mucus from the lungs of people with cystic fibrosis.Folic acid; a vitamin, helps bodies of sickle celled people produce red blood cells.Because of education and job training people with down syndrome can work in hotels, banks, restaurants, an so on.