INHERITED DISEASES Flashcards
abbreviation of CF
Cystic fibrosis
symptoms of cf
Accumulation of mucus
Recurrent infection with Pseudomonas aeruginosa
Excessive inflammation in the lungs
what is CF
CF is a multisystem autosomal recessive disorder affecting the pulmonary, gastrointestinal and reproductive organs
on chromosome 7 what does cf gene codes for
for the CF transmembrane conductance regulator protein (CFTR).
what causes CF
to different mutations on the CFTR protein
what is cf gene involved in
in the transport of Sodium, Potassium, and ATP as well as chloride conductance
how is CFTR mutations diagnosed
DNA testing
What is hereditary hemochromatosis (HH)
HH is an autosomal recessive disorder of iron regulation
mention 4 reason why DNA is perfomed
- Confirm diagnosis
- Determine prognosis
- Prenatal testing
- Identify family members at risk
- Newborn screening for early diagnosis
- Screening of expectant couples or couples considering having children
How is hereditary hemochromatosis characterised
deposition of iron in the tissues
What type of genetic disorder is Hemochromatosis (HH) and what does it regulate
Hemochromatosis (HH) is an autosomal recessive disorder that regulates iron.
What tests are conducted once mutations of the HFE gene are confirmed
Once mutations of the HFE gene are confirmed, transferrin saturation, serum ferritin, and DNA testing of at-risk family members are conducted.
Why is it important to perform DNA testing on at-risk family members once an HFE gene mutation is confirmed?
It is important to perform DNA testing on at-risk family members to identify those who may also have the mutation and be at risk of developing Hemochromatosis, allowing for early intervention and management.
Which gene is analyzed to assess mutations associated with Hemochromatosis and on which chromosome is it located
The HFE (Homeostatic Iron Regulator) gene is analyzed to assess mutations associated with Hemochromatosis. It is located on Chromosome 6.
What type of genetic disorder is Hereditary Hemochromatosis (HH) and what does it regulate?
Hereditary Hemochromatosis (HH) is an autosomal recessive disorder that regulates iron
What characterizes Hereditary Hemochromatosis (HH)?
HH is characterized by the deposition of iron in tissues.
Which gene is analyzed to assess mutations associated with Hereditary Hemochromatosis and on which chromosome is it located?
The HFE (Homeostatic Iron Regulator) gene is analyzed to assess mutations associated with Hemochromatosis. It is located on Chromosome 6.
What tests are conducted once mutations of the HFE gene are confirmed?
Once mutations of the HFE gene are confirmed, transferrin saturation, serum ferritin, and DNA testing of at-risk family members are conducted.
Why is DNA testing of at-risk family members important once an HFE gene mutation is confirmed?
DNA testing of at-risk family members is important to identify those who may also have the mutation and be at risk of developing Hemochromatosis, allowing for early intervention and management.
What is the role of transferrin saturation and serum ferritin tests in the context of Hereditary Hemochromatosis?
Transferrin saturation and serum ferritin tests help measure iron levels in the blood, which can indicate iron overload, a key characteristic of Hereditary Hemochromatosis.
What is Carbamoyl phosphate synthetase I (CPS I) deficiency and how is it inherited?
CPS I deficiency is an autosomal recessive error of metabolism located on Chromosome 2
Where in the cell is CPS I found, and what is its role in metabolism?
CPS I is found in the mitochondrial matrix and it catalyzes the first step of the urea cycle.
What are the clinical consequences of CPS I deficiency?
CPS I deficiency is characterized by the accumulation of ammonia, which can lead to coma and death
How is DNA testing for CPS I deficiency performed?
DNA testing for CPS I deficiency involves indirect testing using linkage studies.
What are linkage studies, and how are they used in the context of CPS I deficiency?
Linkage studies are a method of DNA testing that use highly pleomorphic DNA sequences physically attached to the disease gene to identify genetic mutations.
Explain the significance of the accumulation of ammonia in CPS I deficiency.
The accumulation of ammonia in CPS I deficiency is significant because it is toxic and can lead to severe health issues such as neurological damage, coma, and death if not properly managed
What is the importance of the urea cycle, and how does CPS I deficiency affect it
The urea cycle is crucial for converting ammonia into urea for excretion. CPS I deficiency affects the urea cycle by preventing the proper conversion of ammonia, leading to its toxic accumulation.
what is achondroplasia
The most common form of human genetic dwarfism, inherited as an autosomal dominant trait.
What is achondroplasia and how is it inherited?
Achondroplasia is the most common form of human genetic dwarfism, and it is inherited as an autosomal dominant trait.
What is the consequence of inheriting two mutated alleles of the gene associated with achondroplasia?
Inheritance of two mutated alleles is lethal.
Which gene is associated with achondroplasia, and on which chromosome is it located?
The gene associated with achondroplasia is FGFR3, which is located on Chromosome 4
What protein does the FGFR3 gene code for?
The FGFR3 gene codes for the fibroblast growth factor receptor 3 protein.
What does DNA testing for achondroplasia involve?
DNA testing for achondroplasia involves the direct identification of FGFR3 gene mutations
What is the purpose of prenatal testing for achondroplasia?
Prenatal testing is performed to confirm the diagnosis of achondroplasia.
What type of genetic disorder is Huntington disease and how is it inherited?
Huntington disease (HD) is an autosomal dominant late-onset neurodegenerative disorder.
What are the main clinical characteristics of Huntington disease?
HD is characterized by frequent, involuntary, rapid movements and dementia.
What is the molecular basis of Huntington disease?
The molecular basis of HD is an increase in the number of repeated glutamine-encoding CAG codons in the exon of the HD gene.
On which chromosome is the HD gene located?
The HD gene is located on Chromosome 4.
How is DNA testing for Huntington disease performed?
DNA testing for Huntington disease is performed using PCR, which allows the exact number of CAG repeats to be determined.
What is the role of PCR in diagnosing Huntington disease?
PCR (Polymerase Chain Reaction) is used to amplify and determine the exact number of CAG repeats in the HD gene, which is crucial for diagnosing Huntington disease.
Can prenatal testing be performed for Huntington disease, and if so, how?
Yes, prenatal testing can be performed for Huntington disease to confirm the diagnosis by testing the fetus for the number of CAG repeats in the HD gene
What is Trisomy 21 also known as?
Down syndrome
What causes Trisomy 21?
It is caused by the inheritance of an extra chromosome number 21.
How does Trisomy 21 affect the development of the body and brain?
It causes the body and brain to develop differently than a child without the syndrome
What medical conditions may be associated with Down syndrome?
Thyroid disease and heart disease
List three characteristics or symptoms associated with Down syndrome.
Distinct facial appearance, intellectual disability, and developmental delays.
How does the risk of having a baby with Down syndrome change with maternal age?
The risk increases as a woman ages
diagnosis and screening of trisomy 21
- Prenatal screening may be done on amniotic fluid or chorionic villus sample
- Post-natal diagnosis can be done on the baby’s blood to look for chromosomal abnormality
- The mother can also be checked for chromosomal abnormality
mention stages involved in karyotypying
- collecy 5ml venous blood
- add phytohemagglutinin
- culture at 37 degree celcius
- add colchicine and hypotonic saline
- cells fixed
- spread cells onto slide by dropping
- digest with trypsin and stain with giemsa
- analyze metaphase spread
- karyotype
What is another name for Trisomy 13?
Patau syndrome
What causes Trisomy 13
Trisomy 13 is caused by an error in cell division called nondisjunction, resulting in an extra copy of chromosome 13.
What are some of the intellectual and physical abnormalities associated with Trisomy 13?
Trisomy 13 is associated with severe intellectual disability and physical abnormalities such as heart defects, brain or spinal cord abnormalities, very small or poorly developed eyes, extra fingers or toes, an opening in the lip (cleft lip) with or without an opening in the roof of the mouth (cleft palate), and weak muscle tone (hypotonia).
How does Trisomy 13 affect the eyes?
It can cause very small or poorly developed eyes
What are the common physical abnormalities in the extremities seen in Trisomy 13?
Individuals with Trisomy 13 may have extra fingers or toes.
What type of muscle tone is often observed in individuals with Trisomy 13?
Weak muscle tone, also known as hypotonia
What facial abnormalities are associated with Trisomy 13?
An opening in the lip (cleft lip) with or without an opening in the roof of the mouth (cleft palate).
What congenital heart conditions are commonly associated with Trisomy 13?
Trisomy 13 is often associated with heart defects.
What neurological abnormalities might be seen in individuals with Trisomy 13?
Brain or spinal cord abnormalities.
Explain the term ‘nondisjunction’ and its role in Trisomy 13.
Nondisjunction is an error in cell division that results in an extra chromosome. In the case of Trisomy 13, nondisjunction causes an extra copy of chromosome 13
What is another name for Trisomy 18
Edwards syndrome.
What causes Trisomy 18?
Trisomy 18 is caused by an extra copy of chromosome 18.
List some common physical defects associated with Trisomy 18
Common physical defects include cleft palate, clenched fists with overlapping fingers that are hard to straighten, defects of the heart, lungs, kidneys, and stomach/intestines, and deformed feet.
Describe the characteristic hand abnormality seen in Trisomy 18.
The characteristic hand abnormality is clenched fists with overlapping fingers that are hard to straighten.
What type of congenital defects are commonly associated with Trisomy 18?
Defects of the heart, lungs, kidneys, and stomach/intestines.
What facial abnormality is associated with Trisomy 18?
Cleft palate
How do the physical abnormalities in Trisomy 18 affect the feet
Trisomy 18 often results in deformed feet
