Problem No. 1
Inborn
Errors of Metabolism
Due Tuesday, February 12, 2002
Each enzyme of intermediary metabolism catalyzes a specific chemical reaction. When all are functioning properly, as is usually the case, there are no problems. Even if the activity of one enzyme is ~50% of normal, the effects are usually minimal, such as when someone inherits a mutated gene encoding a defective enzyme from only one parent. However, if a person inherits the same mutated gene from both parents, there is virtually no activity for the encoded enzyme. This leads to serious metabolic problems that often are fatal. Such "inborn errors of metabolism" affect more than one in every 1000 births. While the prognosis is bleak in many cases, restricted diets can ameliorate the effects of some enzyme deficiencies. The key is early detection.
The New York Times recently reported (January
29, 2002, pD7) that newborn infants in some states are routinely tested
for up to a dozen treatable defects. The tests require a few drops of blood
taken from the heel at birth. Based on the month of your birth, please
write a short paper (no more than 4 pages double-spaced) on one of the
following treatable inborn errors of metabolism mentioned in the NYT article.
| Your Birth Month | Your Assigned Inborn Error of Metabolism |
| January or July | PKU (phenylketonuria), |
| February or August | MCAD (medium-chain acylCoA dehydrogenase) deficiency |
| March or September | Biotinidase (multiple carboxylase) deficiency |
| April or October | Maple syrup urine disease (branched-chain ketoaciduria) |
| May or November | Galactosemia |
| June or December | Homocystinuria |
This assignment has several purposes:
1. To familiarize you with one inborn error of metabolismThis assignment will be evaluated on the following elements:
2. To review material from CHEM-641.
3. To illustrate the importance of an understanding of metabolism
4. To demonstrate your ability to locate and use relevant information resources
5. To exercise your organizational and writing skills
1. A clear description of the symptoms and consequences of the untreated disease.Suggestions:
2. The treatment and rationale for the treatment.
3. A discussion of the normal enzyme that is missing in the afflected individuals (e.g. structural properties, reaction catalyzed with chemical structures, cofactors, mechanism, organ and subcellular distribution, any regulatory properties, etc.)
4. How deficiency is detected in newborn infants.
5. Relevant information cited appropriately in the text and the sources listed in standard scientific reference format. A minimum of three primary references must be cited.
6. Turned in on time.
1. Search your topic in PubMed and Web of Science. These are resources you should find helpful in other science courses as well.
2. Get started early and be considerate.. Use your resources in the library and return them to the stacks so that others can use them.