Genetic Influence in Diseases Flashcards
Autosomal Recessive Disorder
occurs when a mutated recessive and diseased gene partners up with an allele thtat is also reccesve and diseased.
autosomal- on chromosome 1-22
example of autosomal recessive disorder
Sickle cell anemia
if during fertlization a person inherits sicekle cell disease gene from mom and a sickle cell gene from dad, this person would have a homozygous genotype of recessive sickle cell genes ; dd
those abnormal recessive alleles will code for abnormally shaped hemoglobin, which make the RBC’s sickle shaped. which means they are more easily damaged or destroyed going through the bloodstream, results in less than normal numbers of RBC’s- Anemia
Phenotype of sickle cell anemia
their phenotype is having the Signs and Symptoms caused by the genotype and patho development
A) SOB, weakness and fatigue, due to decreased O2 being carried to tissues of the body, decreased carrying capity is becuase of
1) anemia- less numbers of RBC’s that carry the hemblobin that carry the oxygen
2)deformed hgb cannot carry the usualy numbers of 02 molecules.
b) ischemic pain, especilaly in the joints
1- the deformed RBC’s clog up the capillaries that usually carry 02 blood to the tissues
2- results in distal tissues that are startved to 02 cry out in pain.
ischemia- cells arent getting enough oxygen due to a circulatory malfunction
pain in the tissue that is not getting enough xygen is ischemic pain.
Heterozygous genotype for sickle cell anemia
the normal gene is dominant over the diseased gene and will not have the disease but can pass it on to the child.
1) called being a carrier genotype Dd is a sickle cell carrier
2) rarely a carrier wil have a milder phenotype of the disease- mild signs and symptoms is called having the trait. someone with sickle cell trait has the genotype Dd but has mild sign and symptoms of sickle cell disease.
autosomal dominant disorders
occurs when a person inherits a mutated, diseased gene that is domiant and the normal gene is recessive.
example of autosomal dominant disorder
Polyscystic kidney disease or PKD— genotype of PP or Pp.
on a certain pair of chromosomes, a pair of alleles has the job for coding the creation of normal kidney tissue
if during fertilization a person inherits kidney tissue gene that has a meutation, that domiant gene will code for abnormal kidneys. in PKD reults in kidney tissue developing cysts which reduce kidney functions and lead to kidney failure.
S & S
hematuria( blood in urnine), poteinuria and frequent kidney infections
b) pain at costverterbal angles and abdomen
c) kidney stones
Genetic disorders
A disease caused by abnormalities in an individuals genetic material.
Groups of genetic disorders
Inherited: ex) sickle cell disease is caused by an inherited, altered gene
Spontaneous: free radicals form as a result of aging- causes damage to dna- protein synthesis altered leading to mutations- an onco gene develops which causes rapid cell growth- cancer may develop
Categorization of genetic disorders
Mitochondrial DNA genetic disorders- need to know exist
Multi factorial genetic disorders
Teratogenic disorders;
Chromosomal disorders-
single gene disorders
multifactorial genetic disorders
Multi factorial genetic disorders- many factors such as environmental triggers, mutations of genes, and sometimes inherited tendencies. Ex) lung cancer beings by smoke and toxins irratating bronchial tissue, one or more genes in cells
Of that tissue begin to be deranged- onco gens created- code for cancer cells
Ex) coronary heart disease(CAD) , DIABTIES MELLUITUS not only stem from inherited gene but other factors that contribute toward it
teratogenic discorders
Teratogenic disorders; a teratogen is any influence- such as drugs, radiation, viruses, that can cause congenital defects.
Ex) fetal alcohol syndrome(FAS)- occurs because toxicity of alcohol causes gene mutations during gestational development. Ex) thalidomide babies- given to women during
50’s that helps with pregnancy nausea, resulted in babies born with abnormal arms and legs due to the drug. The drug was a teratogen.
chromosomal disorders
Chromosomal disorders- type of genetic disorder that results from alterations to the development or structure of a chromosome.
2 sub categories
- Alteration number of chromosomes. Too few or too many
1) Down syndrome is a disorder of abnormal numbers of chromosomes and is sometimes associated with pregnancies of women older than 35.
2) it is a glitch that occurs in very early cellular division and the fetus ends up with 47 instead of 46.
3) extra chromosome appears on the 21st chromosome and has 3 instead of two, thus the name trisomy 21
Phenotype; mental retardation, low set ears, short limbs, larger than normal tongue
- Alteration to the structure of chromosomes- Philadelphia chromosome
1) caused by alterations in chromosomal deletion, duplication, rearrangement.
Single gene disorders
Are inherited
In recognizable patters; autosomal dominant
Autosomal recessive
Sex linked
