* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Human Genetic Disorders
Heritability of autism wikipedia , lookup
Genome evolution wikipedia , lookup
Gene therapy wikipedia , lookup
Gene expression programming wikipedia , lookup
Pharmacogenomics wikipedia , lookup
Biology and consumer behaviour wikipedia , lookup
Neuronal ceroid lipofuscinosis wikipedia , lookup
Quantitative trait locus wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Epigenetics of neurodegenerative diseases wikipedia , lookup
Behavioural genetics wikipedia , lookup
Heritability of IQ wikipedia , lookup
Oncogenomics wikipedia , lookup
Genetic drift wikipedia , lookup
History of genetic engineering wikipedia , lookup
Genetic code wikipedia , lookup
Medical genetics wikipedia , lookup
Koinophilia wikipedia , lookup
Public health genomics wikipedia , lookup
Human genetic variation wikipedia , lookup
Designer baby wikipedia , lookup
Genetic engineering wikipedia , lookup
Genetic testing wikipedia , lookup
Frameshift mutation wikipedia , lookup
Population genetics wikipedia , lookup
Genome (book) wikipedia , lookup
Human Genetic Disorders Biology Mutations • Sometimes genes are damaged or copied incorrectly. • A change in a gene is called a mutation. • Mutations are a source of the variation a species needs in order to adapt to changing conditions over time. • Most mutations are harmful or neutral, only rarely are they beneficial. Recessive Mutations • Most mutations are passed from parent to offspring without being expressed. • Although rare, most people are probably carriers for a number of genetic mutations. • It is unlikely that two individuals with the same unexpressed mutation will mate and produce an offspring expressing the mutation. Genetic Disorders • Particular mutations have become more common in human populations. • The harmful effects that some mutations produce are called genetic disorders. • A person with a genetic disorder has inherited a defective gene from both parents. Cystic Fibrosis • Caused by a faulty transport protein. • This mutation causes mucus accumulation in the lungs and pancreas, causing difficulty breathing and blocking proper food digestion. • There is no cure, only treatment of symptoms. Sickle Cell Anemia • Results from faulty hemoglobin. • This mutation causes the body to make an abnormal form of hemoglobin, making red blood cells looked deformed. • Sickled cells are fragile and break down easily. • Symptoms include fatigue, headaches, muscle cramps, and sometimes kidney or heart failure. Hemophilia • Results from a fault blood-clotting protein. • This mutation causes the body to build a defective form of a protein needed to clot blood. • Small cuts do not heal well and internal bleeding can be fatal. • This trait is sex-linked, meaning it is transmitted on the X chromosome. Only boys will develop the disorder. • There is treatment and children with hemophilia can lead normal lives. Down Syndrome • A genetic disorder caused by an extra chromosome 21. • Features include extra folds in the upper eyelids, broad flattened noses, short stature, and varying degrees of mental retardation. • Occurs in about 1 of every 1,000 births and is more common among babies born to older mothers. Mothers 45 and older have a 1 in 16 risk of having a child with Down Syndrome. Genetic Counseling • A genetic counselor can prepare a family pedigree or record that shows inheritance patterns over several generations. This can help determine the chance of being a carrier for that disorder. • We also have genetic testing now and we can test for the presence of specific genes known to cause genetic disorders. Finding Cures • Most genetic disorders cannot be cured. • Therapy is available for some. • Techniques in genetic engineering can make it possible to cure genetic disorders by replacing copies of defective genes with copies of healthy ones. • Gene therapy is an evolving science.