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10 Cards in this Set
- Front
- Back
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NB: genetic variation |
Occurs through new mutation and "shuffling" of parental variation (sexual reproduction)
Determines complex development and maintenance
In charge of how we sense and communicate (sight - Rhodopsin; hearing - gap junction; pain - sodium channels; seech - FOXP2)
Important in succeptibility to Disease |
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What type of genetic disorders can you think of? |
Single gene disorders single gene mutation lead to disease e.g. cystic fibrosis
Chromosomal disorders change, gain, loss or exchange of chromosome elements e.g. Turner Syndrome, Down syndrome (DS severity is polygenic)
Polygenic disorders multifactorial diseases; combined effect of many genes and/or environment e.g. diabetes
Somatic disorders disorders of somatic cells (non-germ-line) e.g. cancer |
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Describe the effect and frequency of genetic variants |
Low penetrance observed at most common allele frequency;
Higher the allele frequency, the less the effect |
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Give the 4 most common disease associated mutation types |
Nonsense mutation - A.A change to stop codon Missense mutation - single nucleotide change (point mutation) new codon codes for different AA Splice-site mutation - insertion/deletion of n. of nucleotides in specific sites at which intron splicing occurs Insertion or deletion mutation - add/loss of one or more nucleotide base pairs in DNA sequence |
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State the number of the protein coding geneome varients and give its Exome size |
~ 22,500 variant 35.9Mb |
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Rare inherited diseases stats:
Size in population
n. of people in UK
n. of rare disorders
population freq. of single gene defect
reason for early intervention |
Less than 5% of population
3 million people in UK
7000 rare disorders (disabling, short life, costly)
85% single gene defect
Helps avoid disability; better clinical care |
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Give a simplified step process for making designer babies |
Know genetic variant/mutation to select for/exclude
Need legal permission for selection
IVF, then pre-implantation genetic diagnosis (PGD)
Luck |
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Optimal time for PGD? |
Pre-implantation genetic diagnosis:
at blastomere, +1 cell remove, chromosome tested;
embryo replantation based on results |
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Why don't drugs work in all patients? |
- Dependent on genetic variation e.g. SNP in various cellular pathways Variation in absortion; Disctribution; Metabolism; elimination; variability of target receptors
- Same disease due to independent and diverse pathological and genetic processes |
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Pharmacogenetics states that DNA variation e.g. SNPs affect drug efficacy
What's the importance of genome sequencing? |
- Healthcare: right diagnosis, drug and dosage;
- Personal lives: help with family planing and risk management; |
