8 terms

Ch. 12 Genetic Disorders

Cystic Fibrosis
1 in 3500 - one of the most common recessive genetic disorders among Caucasians which affects the mucus-producing glands, digestive enzymes, and sweat glands. Cause: The gene that codes for a membrane protein is defective. Effect: Excessive mucus production and digestive and respiratory failure. Cure/Treatment: No cure, Daily cleaning of mucus from the lungs. Mucus - thinning drugs. Pancreatic enzyme supplements.
the most common congenital disease; the child's lungs and intestines and pancreas become clogged with thick mucus; caused by defect in a single gene; no cure is known.
Simple Dominant Traits
traits that appear in the F1 generation
Tay-Sachs Disease
1 in 2500 - recessive genetic disorder. Often identified by a cherry-red spot on the back of the eye and is predominant among Jews of eastern European descent. affects people of Jewish descent - Cause: Absence of a necessary enzyme that breaks down fatty substances. Effect: Buildup of fatty deposits in brain inflates nerve cells and causes mental disabilities.
Huntington's Disease
a dominant genetic disorder that affects the nervous system and occurs in one out of 10,000 people in the U.S. The symptoms first appear between 30 and 50 yrs. old. Symptoms: gradual loss of brain function, uncontrollable movements, and emotional disturbances. Genetic tests are available to detect this dominant allele. No cure or treatment.
Phenyl Ketonuria
a genetic disorder of metabolism; lack of the enzyme needed to turn phenylalanine into tyrosine results in an accumulation of phenylalanine in the body fluids which causes various degrees of mental deficiency. an inborn error of metabolism caused by the lack of an enzyme, resulting in abnormally high levels of the amino acid phenylalanine; untreated, PKU can lead to severe, progressive mental retardation.
congenital tendency to uncontrolled bleeding; usually affects males and is transmitted from mother to son. is a group of hereditary genetic disorders that impair the body's ability to control blood clotting or coagulation, which is used to stop bleeding when a blood vessel is broken. ...
Dominant vs. Recessive
Dominant: Mendel's name for a specific trait that appeared in the F1 generation. Recessive: Mendel's name for a specific trait hidden or masked in the F1 generation.
Punnett Square
a diagram that is used to predict an outcome of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach, and is used by biologists to determine the probability of an offspring having a particular genotype.A learning tool for determining the possible outcomes of a given cross between individuals. It was developed by RC Punnett, an early British geneticist.