Genetic Factors And Disease Flashcards
(23 cards)
What conditions does folate deficiency increase the risk of?
- spina bifida
- cleft lip/palate
What is the genotype?
Genetic constitution of an individual.
What is the phenotype?
The physical, biochemical and physiological features of an individual which result from the interaction of the environment and the genotype.
What is an allele?
One of several alternative forms of a gene at a specific locus.
What is polymorphism?
Frequent hereditary variations at a locus.
What does hemizygous mean?
Only one allele refers to a locus on an X chromosome in a male.
What is a karyotype?
A laboratory technique that produces an image of an individual’s chromosomes. Used to detect chromosomal abnormalities, picks up on deletions/duplications greater than 5 Mbps in length.
What is an acrocentric chromosome?
A chromosome where the centromere is located close to one end.
What is an autosomal dominant inherited disease?
A disease which manifests in the heterozygous state.
Why can a father not pass on an X-linked condition to his son?
Father passes on Y chromosome to son.
What is an autosomal recessive inherited disease?
A disease which manifests in the homozygous state.
What is a risk factor for recessive inheritance?
Consanguinity (reproduction between cousins)
What is X-linked recessive inheritance caused by?
A pathogenic allele on the X chromosome?
What is an example of an X-linked disease?
Haemophilia
Why is Y-linked inheritance rare?
Genetic variants on Y are often linked to infertility so they’re not passed on.
What structure does mitochondrial DNA form?
Ring shaped chromosome.
Are all mitochondrial proteins coded for by mitochondrial DNA?
No, some are coded for by nuclear DNA.
How are mitochondrial diseases inherited?
From mother, if gene variant is on the mitochondrial chromosome.
What is imprinting?
When a carbohydrate group is added to the promoter region of an allele to inactivate it. Only 1 allele is active. For some genes it is always the paternal or maternal allele that is imprinted.
What is familial hypercholesterolaemia?
When some people have a pathogenic allele for the LDL receptor, so increased risk of coronary heart disease.
How does high cholesterol increase risk of coronary heart disease?
Lipoproteins are formed when lipids associate with cholesterol in the liver. High levels of low density lipoproteins are associated with an increased risk of coronary heart disease.
Which genes increase risk of breast and ovarian cancer?
BRCA genes.
How can you inherit Alzheimer’s / Parkinson’s?
Alzheimer’s - pre-senilin 1 variants
Parkinson’s - LRRK2 variants
