Gene & Chromosomal mutations Flashcards
genotypic variability
difference in the combination of alleles present in the genome.
- variations in the genetic makeup.
phenotypic variability
variations in the observable traits, influnded by both genetic and environmental factors.
desrcibe genetic drift
when chance dictates which alleles are passed on.
works along natural selection to drive evolution.
- drift has a greater effect in smaller populations. cos in larger populations chance in allele frequency evens out.
Aneuploidy
abnormal number of chromosomes, often due to nondisjunction during cell division.
polyploidy
presence og multiple cets of chromosomes common in plants.
give examples of autosomal dominant disorders
- Huntingtons disease
- Polycystic kidney disease (PKD)
- Neurofribromatosis type 1 (NF1)
Huntington’s disease
a neurodegenerative disorder - affecting motor and cognitive functions.
- by a mutation in the HTT gene on chromosome 4.
Neurofibromatosis Type 1
(NF1)
tumour gorwth in nerve tissue, skin pigmentation changes
- mutations in the NF1 gene.
Polycystic Kidney Disease (PKD).
formation of flluid filled cycts in the kidneys.
PKD1 or PKD2 genes are responsible.
give examples of autosomal recessive disorders
cystic firbrosis
sickle cell anemia
phenylketonuria (PKU)
phenylketonuria (PKU)
inability to metabolise phenylalanine, leading to intellectual disabilities.
- caused by PAH genes.
- an inborn error in metabolism.
what mutation causes sickle cell anemia
mutations in HBB gene.
- abnormal heamoglobin = misshaped RBCs
cystic fribrosis
respiratory and digestive dysfunciton cos of thick mucus production
- mutation in the CFTR gene
Fragile X syndrome
- what type of syndrome is it.
- what are symptoms
- what genes are impacted.
- an X-linked dominant disorder.
- intellectual disabilities, behavioural changes.
- expansion of CGG repeats in the FMR1 gene on the X chromosome.
normally the CGG trplet it repeated about 5-40 times, but with the mutation, it is repeated upto 200 times.
give examples of V-linked reccessive disorders
- Duchenne Muscular Dystrophy (DMD).
- Heamophillia A and B
Duchenne Muscular Dystrophy (DMD).
- progressive muscle weakness and wasting.
- mutations in the DMD gene.
give examples of mitochondrial disorders
- Laber’s Hereditary Optic Neuropathy (LHON).
- Mitochondrial Myopathy.
descrive the laber’s hereditary optic neuropathy disorder
vission loss from damage to the optic nerve.
- accosiated with mitochondiral DNA mutations.
what is Mitochondrial Myopathy.
results in muscle weakness and fatigue. again from mutations in mitochondrial DNA, affecting energy production.
give examples of multifactorial disorders
- Alzheimer’s disorders
(progressive neurodegenerative disorder affecting memory and cognitive functions.) - type 1 & 2 diabetes.
(metabolic disorder, from insulin resistance.
both are influenced both by genetic predisposition and lifestyle factors.
other examples = cancers, migraines.
examples of chromosomal disorders
down syndrome (trsiomy 21) - intellectual disabilities.
turner syndrome - females - monosomy X
Klinefelter - in males - XXY
what are inborn error of metabolism
A heterogeneous group of disorders that may be inherited or may occur as the result of spontaneous mutation.
other than PKU, give another example of inborn errors of metabolism.
Gaucher Disease - accumulatio of fatty substances in cells.
- mutations in GBA gene.
what can me done to test for and diagnose inherited diseases.
describe 4 ways.
carrier testing
parental screeneing
parental diagnostic testing
newborn screening
how is carrier testing done.
tests if either parent is carrying a mutation to a disorder.
how is parental screening caried out.
blood tests from the pregnant mum, how likely the fetus might have a condition.
how is Prenatal diagnostic testing done
testes a sample of the fluid in uterus, to find whether developing fetus might have a higher risk for a condition.
how is Newborn screening done.
samples newborn’s blood and to detect any disorders.
- done to all babies in ohio.
what is edwards syndrone
aka trisomy 18.
- some can have a whole extra chromosome 18, some may have it only in some cells, and someimes there will only be extra sections on the same chromosome.
aka - full, mosain and partial edward’s syndrome.
gene mutations can either be
Dominant or recessive
what are numerical mutations
mutations that occur in the chromosome count, potentially causing aneuploidies or polyplodies.
result of cell division errors
Structural mutations include
Lost, replicated, inverted fragments of chromosomes
