BIOL 1001 Study Guide - Phenylalanine, Phenylketonuria, Familial Hypercholesterolemia
Document Summary
Caused by mutations in cftr (cystic fibrosis translocator) gene. (ctfr protein) Gene encodes a defective channel protein in membrane of cells, in exocrine glands. Cf-glands secrete abnormally thick mucus due to osmotic imbalance. Interferes with breathing, pancreatic function, and allows growth of bacteria due to mucus production. Gene for cftr located on human chromosome 7. In heterozygotes, harmful allele is masked but can still be passed on to offspring. Each chromosome has a short arm (p arm) and a long arm (q arm) Karyotype: a picture of the chromosomes in a cell that is used to check for abnormalities. A karyotype is created by staining the chromosomes with dye and photographing them. The photograph is then cut up and rearranged so that chromosomes are lined up into corresponding pairs. If parents are both heterozygous (carriers), child will have a 25% chance of being affected.
