Intro to Medical Genetics

Question 1

What are the model organisms for understanding human genetics?

Answer 1

• E. Coli (bacteria)
• S. cerevisiae (yeast)
• Drosophila melanogaster (fruit fly)
• C. elegans (roundworm)
• Mus musculus (mouse)

Question 2

What can we study using Drosophila as a model organism?

Answer 2

Homeobox genes or HOX genes

• pattern the principal axes of the body
• code for developmental programs that dictate positional information to allow structures to develop in the appropriate places
• best characterized genes

Question 3

How many genes were identified by the Human Genome Project?

Answer 3

20,000

Note: this was revised from the estimated 35,000 genes due to the importance of transcription factors more so than differences in genes and because there are similarities of multiple regions

Question 4

What is OMIM and how is it helpful?

Answer 4

Online Mendelian Inheritance in Man: it is a database that serves as an up to date reference for genetic conditions

Note: each condition has a unique 6 digit number

Question 5

What are the 4 types of single gene mutations?

Answer 5

Silent, Missense, Nonsense, Frameshift

Question 6

What genetic disease served as the first demonstration that a mutation in a structural gene could cause an amino acid substitution in the corresponding protein?

Answer 6

Sickle Cell Disease

Question 7

1 in ___ newborns has a single gene or chromosomal disorder

Answer 7

60

Question 8

What percentage of admissions do genetic conditions account for? (Peds? Adults?)

Answer 8

30% of peds

10% of adults

Question 9

1 in ___ people under age 25 has a genetic disorder

Answer 9

20

Question 10

What are the 4 types of genetic disorders?

Answer 10

Chromosome, Single-gene, Multi-factorial, Mitochondrial

Question 11

Name 3 examples of nontraditional inheritance patterns

Answer 11

microdeletion syndromes, imprinting, trinucleotide repeat expansion