Lecture 2: Intro To Medical Genetics Flashcards
What are four inborn errors of metabolism?
Alcaptonuria, cystonuria, pentosuria, albinism
What is an INBORN ERROR OF METABOLISM?
Genetic biochemical disorder - single enzyme defect produces a metabolic block. Recessive.
What is alcaptonuria?
Inborn error of metabolism. Accumulation of homogentisic acid in the blood. Damage to cartilage, heart, kidney.
Which enzyme is mutated in albinism?
Tyrosine oxidase. Inborn error of metabolism.
In PKU: 1. what is mutated, 2. what does the mutation prevent, and 3. what accumulates as a result?
- Phenylalanine hydroxylase (PAH)
- Prevents conversion of phenylalanine (PHE) to tyrosine
- Phenylalanine accumulates
How can PKU be detected?
Phenylpyruvic acid in the urine
Some PHE can be converted to phenylpyruvic acid
In the rare case of a live birth, how can PKU be treated?
Diet modification
What is locus heterogeneity?
Mutations in different genes can lead to the same phenotype
What does a mutation in the genes involved in the BH4 pathway lead to? And which neurotransmitters does this affect?
Hyperphenylalanineanemia
Serotonin and dopamine
Make the ploidy of a cell during mitotic division.
2N –> 4C –> 2N
Which method of cell division involves reduction division?
Meiosis
Map the ploidy of a cell undergoing meiotic division
2N –> 4C –> 2N –> N
What do 2C and 4C represent, respectively?
ssDNA
dsDNA
Does recombination/crossing over happen on homologous or non-homologous chromosomes?
Homologous
What is reduction division?
During meiosis I, centromeres remain together and homologs separate.
