Flashcards in Student Presentations Deck (67)
What is Familial Adenomatous Polyposis?
Polyps precursor to colorectal adenocarcinoma
Multiple adenomatous polyps
When polyps become large they cause blood in faeces
What are the three types of FAP?
Hyperplastic, Pedunculated and sessile
What pathway is involved in FAP?
APC complex dissociates from membrane and binds Beta catenin which is labelled by ubiquitin for degradation and prevents transcription. When the Axin binds to the LRP intracellular protein (bound to Wnt) the Beta catenin is free to initiate gene transcription.
What kind of mutations can cause FAP?
Beta catenin binding sites
Axin binding sites
Germ line mutations
How is FAP managed and prevented?
How is FAP treated?
Proctocolectomy with ileal pouch anal anastomisis
Subtotal/Total colectomy with ileorectal anastomosis
Total proctocolectomy with ileostoy
What mutations are needed for the polyps to cause cancer?
K-ras and P53 mutations
What are some current research areas for FAP?
Medical and surgical techniques
What is cystic fibrosis?
A monogenic disorder from CFTR mutation causing errors in chloride ion movement across the apical membrane and changes in electrical potential and other ion movement.
What are the symptoms of cystic fibrosis?
Excess mucus through exocrine organs
Affects respiratory, digestive and reproductive systems.
How do you diagnose cystic fibrosis?
Clinical features and sweat testing i.e. analysis of saltiness and chloride ion concentration
What are some cystic fibrosis treatments?
Antibiotics and bronchodilators
What is neurofibromatosis?
A disease which involves a genetic mutation (NF1/NF2) causing tumours hanging off or under the skin and causes blindness and sometimes death.
What are vesticular nerve schwannomas?
Distinctive feature of NF2, benign neurofibromas, characteristic of schwannomatosis which is the third form of neurofibromatosis.
What are the genetics of NF?
Mutations within the NF1 gene on chromosome 17 and NF2 on chromosome 22.
Premature STOP codon in NF1 encodes inactive neurofibromin which doesn't inhibit RAS P21 and allows proliferation.
What are some treatment options for NF?
Surgery to remove tumours
Tyrosine kinase inhibitors
What is alpha thalassemia?
Deficient alpha globin chain synthesis
Excess beta globin chains
Can be 1, 2, 3 or 4 deletion thalassemia
What is beta thalassemia?
Decreased beta globin chain production
Beta+ means less beta globin
Beta0 means no beta globin
Can be carrier, reduction or no production
What is thalassemia major?
Defective gene from both parents
Severe anemia, defective growth, fragile bones, yellow skin
Treated with regular blood transfusions and iron chelation therapy
What is thalassemia intermedia?
Severe gene plus mild gene
Paleness and moderate anemia
What is thalasssemmia minor?
Small red blood cells
What is Hb Barr syndrome?
Loss of all 4 alpha globin chains
Build up of excess fluid, anemia, heart defects, genital abnormalities
What is HbH disease?
Loss of 3 alpha globin chains
Mild-moderate anemia, yellow skin, bone deformities
What goes wrong to produce thalassemia?
Glycine and succinyl-CoA form ALA
ALA forms protoporphyrin
Protoporphyrin and iron make heme
Heme combines with globin to make hemoglobin
When this process is disrupted it causes thalassemia
What are the advantages of heterozygous thalassemia?
Carriers have malaria protection against all malaria types
Beta thalassemia heterozygosity provides protection against ischemic heart disease
What is CAH?
When an enzymatic deficiency impedes cortisol production which feeds into the adrenal pathway causing disease.
What are the genetics of CAH?
Gene duplication leading to inactive CYP21A1P 21-OH gene
Small scale gene conversion
Unequal meiotic crossover
What are the population genetics behind CAH?
@common@ human autosomal recessive
Bottleneck effect from WWII
How is CAH prenatally treated?
Synthetic steriod, prevents/reduces virilisation