GiM Flashcards
Southern Blotting
Used for large amounts of DNA
Northern Blotting
Used for RNA
Western Blotting
Used for proteins
PCR
Determines presence/absence (allele-specific) or product size
QF-PCR
Amplifies repeat using fluorescent primers
Products separated by size of repeats
Used in amniocentesis+ chorionic villi biopsy
qPCR
Confirms small copy number variations between pt and control
Oligonucleotide Ligation Assay
Compares 2 alleles with slight differences
Distinguishes between a disease-causing mutation and a normal allele
Sequencing
Sanger= type and place of mutation Clonal= cheaper and faster, used for PCR product, mutated genes and exome panels
FISH
Chromosomes labelled with dye
Identifies copy number imbalances, aneuploidy, cancer
Multiplex Ligation-Dependent Probe Amplification
DNA based PCR
Identifies copy number variations in many loci (right number of DNA)
Microarray CGH
Genome+control DNA compete Does 8 pts at a time Finds genetic imbalances Database identifies pathology of imbalances Needs good quality DNA
Next Generation Sequencing
Similar to microarray CGH with molecular barcode
>1= gain
Familial Inheritance
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Knudsonβs Two Test Hypothesis
Need two mutations in cancer genes to make a tumour
Need 3 generations to say cancer is familiar
e.g. retinoblastoma, FAP, HNPCC, BRCA, Li-fraumeni (p53)
Non-Mendelian
Additive genes e.g. BP, head circumference, weight
Influenced by environ
Diseases= spina bifida, asthma, cancer, DM
Androgenesis
No egg in ovum but fertilised by sperm
Makes hydatiform mole (malignant trophoblastic tumour)
Well developed membranes
Parthenogenesis
Two eggs in ovum+no sperm Benign ovarian teratoma Mostly epithelium (no muscle, membranes or placenta)
Imprinting
Epigenetic
Maternal or paternal copy methylated (silencing it at CG island)
Hypomethylation= Russell-Silver syndrome
Angelman
Deletion in chr 15 on MATERNAL gene
Dysmorphic, seizures, jerky, mental handicap
Prader-Willi
Deletion in chr 15 on PATERNAL gene
Obese, mental handicap, hypergenitalism, hypotonia
X-Inactivation
One X silenced in females
In males, X or Y silenced
Occurs in blastocyst
Cytogenetics
Found via G-banding, FISH or qPCR
Issues= dosage, genes activated/inactivated, gene position changed, unmasking of recessive
Aneuploidy
Increased maternal age increases risk as meiotic structure deteriorates
Edwardβs
Trisomy 18
Microcephaly, clenched hands, mental delay, congenital heart disease