Cystic Fibrosis Muscular Dystrophy Sickle-Cell Anemia Tay-Sachs Disease 25% Affected - has CF 25% Carrier Unaffected carrier mother Unaffected carrier father 25% Carrier 25% Unaffected fatty substance lysosome enzyme Unaffected son Unaffected daughter Carrier daughter Affected son Unaffected carrier mother Unaffected father normal biceps muscle decreased muscle mass due to Muscular Dystrophy dystrophin bundle of muscle fibers whole muscle muscle cell membrane www.newpathlearning.com © Copyright NewPath Learning. All Rights Reserved. 94-4637 Human Genetic Disorders Cystic fibrosis is an inherited condition affecting the cells that produce mucus, sweat and digestive juices. It is caused by a mutation in the gene that regulates the components of these secretions. Normally these secretions are thin, but in people with cystic fibrosis the body produces mucus that is thick and sticky. This abnormal mucus plugs up ducts in the pancreas and lungs leading to digestive and severe breathing problems. Cystic fibrosis occurs in 1 in 2,500 to 3,500 Caucasian newborns. Muscular dystrophy is a group of more than 30 inherited genetic disorders that gradually cause muscle weakness and muscle loss. Duchenne muscular dystrophy is the most common and severe form of the disorder. It affects about 1out of every 3,500 boys. It is caused by the absence of a protein called dystrophin, which helps muscle cells keep their shape and length. Sickle cell anemia is an inherited blood disorder in which the body makes sickle-shaped (crescent-shaped) red blood cells. The underlying cause involves hemoglobin - a component of red blood cells which carries oxygen from the lungs to body organs and brings carbon dioxide back to the lungs. Normal red blood cells are disc-shaped and can move easily through the blood vessels. However, sickle cells contain an abnormal form of hemoglobin that causes the cells to have a sickle, or crescent shape. These cells form clumps and get stuck in the blood vessels which deprives organs and tissues of oxygen-carrying blood. Blocked blood vessels can cause pain, serious infections and organ damage. Individuals with sickle cell anemia have inherited two sickle cell genes, one from each parent. Someone who has inherited only one sickle cell gene will not develop the disease, but will be a carrier for the sickle cell trait. The disease occurs in about 1 in every 500 African-Americans and 1 in every 1000 to 1400 Hispanic-Americans. About 2 million Americans, or 1 in 12 African Americans, carry the sickle cell trait. Tay-Sachs disease is a rare genetic disorder in which harmful quantities of a certain fatty substance build up in tissues and nerve cells in the brain. The disorder is caused by a mutation in a gene for making the enzyme to break down this fatty substance. sickle cells normal RBCs abnormal hemoglobin strand normal hemoglobin pancreas trachea lungs Normal cell - lysosomes break down fatty substance Tay-Sachs cell - enzyme missing from lysosomes Fatty substance builds up - cell eventually dies 25% Unaffected 25% Carrier Unaffected carrier mother Unaffected carrier father 25% Carrier 25% Affected - has Tay-Sachs
Cystic Fibrosis Muscular Dystrophy Sickle-Cell Anemia Tay-Sachs Disease fatty substance lysosome Unaffected son Unaffected daughter Carrier daughter Affected son Unaffected carrier mother Unaffected father \|xiBAHBDy01752tz] www.newpathlearning.com © Copyright NewPath Learning. All Rights Reserved. 94-4637 Human Genetic Disorders Cystic fibrosis is an _________________ ___________________ affecting the cells that produce ________________, _________________ and _________________ ______________. It is caused by a _______________________ in the _______________ that regulates the components of these secretions. Normally these secretions are ____________ , but in people with cystic fibrosis the body produces mucus that is _______________ _______________ and sticky. Muscular dystrophy is a group of more than 30 inherited genetic disorders that gradually cause muscle _________________ and muscle _____________ . ______________________ _________________ _________________ is the most common and severe form of the disorder. It is caused by the absence of a protein called _________________ , which helps muscle cells keep their shape and length. Sickle cell anemia is an inherited blood disorder in which the body makes _____________ _________ (crescent-shaped) red blood cells. The underlying cause involves _________________ - a component of red blood cells which carries oxygen from the lungs to body organs and brings carbon dioxide back to the lungs. Normal red blood cells are _____________ ______________ and can move easily through the blood vessels. However, sickle cells contain an abnormal form of hemoglobin that causes the cells to have a sickle, or crescent shape. These cells form _________________ and get stuck in the blood vessels which deprives organs and tissues of ___________________ blood. Blocked blood vessels can cause _____________________ _____________________. Individuals with sickle cell anemia have inherited two sickle cell ______________ , one from each parent. Someone who has inherited only one sickle cell gene will not develop the disease, but will be a _________________ for the sickle cell trait. Tay-Sachs disease is a rare genetic disorder in which harmful quantities of a certain _________________ _________________ build up in tissues and nerve cells in the brain. The disorder is caused by a _________________ in a gene for making the _________________ to break down this fatty substance. lungs Normal cell - lysosomes break down fatty substance Tay-Sachs cell - enzyme missing from lysosomes Fatty substance builds up - cell eventually dies Key Vocabulary Terms • carrier • Muscular dystrophy • Cystic fibrosis • mutation • gene • red blood cells • hemoglobin • Sickle-cell anemia • inherited condition • Tay-Sachs disease Unaffected carrier mother Unaffected carrier father