- Duchenne muscular dystrophy (DMD) is an X-linked disease for which prenatal diagnostic testing can be performed. Has prenatal genetic testing increased the detection rate of this disease, compared to prior diagnostic methods? If so, how? If not, why? In case the fetus is diagnosed with DMD and parents decide to terminate the pregnancy, are there chances that the next child will also be a carrier of the disease?
- Jane Hill’s husband, Charlie Marlow, has hemophilia A when he marries Hill, who does not have the disorder. Jane’s parents also do not have hemophilia, but her brother Steve Hill does. What is the probability that the Marlows’ son will have the disorder? What is the probability that their daughter will have hemophilia? Are there chances that their daughter will be a carrier of this disorder?
- Which DNA sequence will encode for at least five amino acids? Change three different bases separately (either by addition or deletion) and write the corresponding amino acid sequences that result from these modifications.
- Using the Internet, search and describe a genetic disorder (other than α-thalassemia mental retardation syndrome, immunodeficiency–centromeric instability–facial anomalies [ICF] syndrome, Rett syndrome, and Rubinstein-Taybi syndrome) that results from aberrant chromatin remodeling. Does the disorder result from adding or deleting acetyl, methyl, or phosphate groups? Explain. Does the abnormal chromatin remodeling affect other genes?
- Using the Internet, search and describe a genetic disorder that results from aberrant gene splicing. How does alternative splicing affect the disorder? Where in the gene does the aberrant splicing occur?
Gene mutations can occur spontaneously or could be induced by exposure to chemicals or radiations. Mutations are of various types, ranging from point mutations to expanding repeats. Each mutation is classified by the way it alters the DNA.