Scenario :
You are a second year medical student shadowing an adolescent pediatrician in her office. A 17-year old male comes in with a respiratory infection; this is his fourth respiratory infection this year. He thinks he may have asthma or allergies, and has a family history of lung disease. The pediatrician runs a blood test and finds that the patient has alpha-one antitrypsin deficiency, and asks you to research the disorder.
Go to OMIM ( http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=OMIM&cmd=Limits ):
Search the database for alpha-one antitrypsin deficiency.
Use the item titled “+107400 Protease Inhibitor 1; PI” to answer the following questions.
Note: The website www.alphaone.org may be helpful to clarify what alpha-one antitrypsin deficiency is.
Study Questions:
1. What is alpha-one antitrypsin (AAT) and how does its function relate to neutrophil elastase?
2. Where is the gene that encodes AAT located, and how many variants of AAT have been found?
3. Is there a change in risk for cirrhosis or liver cancer among AAT deficiency homozygotes?
4. Phenotypically, how many AAT deficiency mutations are there, and how do they differ? What conditions are each mutation associated with?
5. Do AAT deficiency heterozygotes experience any effects of being heterozygous for the deficiency?
6. Among AAT deficiency homozygotes, what age groups and gender are most at risk for liver disease? |
