genetic disorders 2.0 Flashcards
What type of genetic inheritance is Huntington’s Disease?
Dominant
Autosomal, no group association.
What causes Huntington’s Disease?
A trinucleotide repeat expansion in the gene coding for Huntingtin (Htt).
What is the result of the trinucleotide repeat expansion in Huntington’s Disease?
It produces an altered form of the Htt protein, mutant Huntingtin (mHtt), leading to neuronal cell death.
What are the initial symptoms of Huntington’s Disease?
General lack of coordination and an unsteady gait.
What is chorea in Huntington’s Disease?
Jerky, random, uncontrollable movements that develop as the disease progresses.
Is there a cure for Huntington’s Disease?
No, it is a terminal illness with no treatment to fully arrest progression.
What is the significance of pre-symptomatic testing for Huntington’s Disease?
It counts the number of repetitions in the gene to determine risk.
What does a negative test for Huntington’s Disease indicate?
The individual does not carry the expanded gene and will not develop symptoms.
What is Sickle Cell Disorder’s mode of inheritance?
Recessive / Codominant.
What mutation causes Sickle Cell Disorder?
A point mutation in the Hgb gene, replacing glutamic acid with valine.
What happens to red blood cells in Sickle Cell Disorder?
They change shape upon deoxygenation, becoming rigid and sickle-shaped.
What is a common symptom of Sickle Cell Disorder?
Periodic painful attacks and shortened life expectancy.
How can Sickle Cell Disorder be detected?
Through a Sickle Solubility test and hemoglobin electrophoresis.
What is the relationship between Sickle Cell Disease and malaria?
Individuals with one or two alleles of the sickle cell disease are resistant to malaria.
What type of genetic inheritance is Cystic Fibrosis?
Recessive.
What gene mutation causes Cystic Fibrosis?
A mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.
What are common symptoms of Cystic Fibrosis?
Difficulty breathing and insufficient enzyme production in the pancreas.
How can Cystic Fibrosis be diagnosed?
Through genetic testing before birth or a sweat test in early childhood.
What is the life expectancy for individuals with Cystic Fibrosis?
Most individuals die young, often in their 20s and 30s from lung failure.
What type of genetic inheritance is Familial Hypercholesterolemia?
Incompletely Dominant.
What causes Familial Hypercholesterolemia?
Defects in the LDL-Receptor gene resulting in malfunctioning LDL receptors.
What are the characteristics of Familial Hypercholesterolemia?
Very high LDL cholesterol and early cardiovascular disease running in families.
How can Familial Hypercholesterolemia be identified?
With genetic testing.
What type of genetic inheritance is Phenylketonuria (PKU)?
Recessive.
What enzyme is deficient in Phenylketonuria?
Phenylalanine hydroxylase (PAH).
What happens if Phenylketonuria is left untreated?
It can cause problems with brain development, leading to mental retardation and seizures.
How is Phenylketonuria detected?
Using the HPLC (High performance liquid chromatography) test.
How can Phenylketonuria be controlled?
With a diet low in phenylalanine and high in tyrosine.
What type of genetic inheritance is Tay Sachs Disease?
Recessive.
What gene mutation causes Tay Sachs Disease?
Mutations on the HEXA gene.
What occurs in Tay Sachs Disease?
Insufficient activity of hexosaminidase A leads to lipid accumulation in brain nerve cells.
What are the symptoms of Infantile Tay Sachs Disease?
Normal development for six months, followed by deterioration of mental and physical abilities.
How is Tay Sachs Disease diagnosed?
With an enzyme assay test and observation of a ‘cherry-red’ spot in the retina.
What type of genetic inheritance is Hemophilia?
Recessive, sex-linked (X).
What is absent in Hemophilia A?
Clotting factor VIII.
What does Hemophilia impair?
The body’s ability to control blood clotting.
How can Hemophilia be managed?
With regular infusions of the deficient clotting factor.
What type of genetic inheritance is Albinism?
Recessive.
What causes Albinism type 1?
An alteration of the tyrosinase gene.
What is the principal effect of Albinism?
Prevents the body from making normal amounts of the pigment melanin.
What is a common characteristic of individuals with Albinism?
They appear white or very pale.
What should people with Albinism do to protect their skin?
Use sunscreen when exposed to sunlight.
What type of genetic inheritance is Achondroplasia?
Dominant.
What gene mutation causes Achondroplasia?
A mutation in the fibroblast growth factor receptor gene 3 (FGFR3).
What is a common characteristic of individuals with Achondroplasia?
Short stature, with an average adult height of just over 4 feet.
How can Achondroplasia be detected?
Before birth by prenatal ultrasound or DNA testing.
What is the outcome of inheriting two copies of the mutant gene in Achondroplasia?
It is invariably fatal before or shortly after birth.
which diseases affect ashkenzani jews
cystic fibrosis and tay sachs
which disease affects sub saharans
sickle cell
