Day 11. Recombinant DNA. Genetic testing

Day 10. Genetics of Common Diseases

• CHD
• diabetes mellitus
• cancer

Day 9. Gene mapping and cloning

Well, I already thought that genetics seems easier, but this subject is tough for me, hard to capture.

Trying to determine where the gene is located and how far apart 2 genes are from one another.

• crossing over (in prophase I of meiosis)
• linked genes - the probability of recombination <>
• syntenic - genes on the same chromosome
• recombination frequency
• LOD scores
• linkage disequilibrium
• polymorhic markers

Gene cloning:

1. find linkage to a known markers;
2. identify protein coding regions (computers - promoter areas, exon-intron boundaries, starting codones, CG islands)
3. compare DNA sequences of these genes in affected and unaffected individuals.

Day 8. Cytogenetics

• Trisomy 21 - Down syndrome
• Trisomy 18 - Edward's syndrome
• Trisomy 13 - Patau syndrome
• Klinefelter's syndrome
• Turner syndrome

Triple screen

SRY gene

Pseudohermophroditism

Day 7. Population Genetics

p + q = 1

pxp +2 pq + qxq = 1

Allpied to autosomal recessive diseases:
pxp - frequency of normal genotype
2pq - frequency of heterozygose carrier
qxq - frequency of mutated genotype

p - frequency of normal allele
q - frequency of mutated allele

Day 6. Genetics. Single-gene Disorders.

Moved to genetics this morning. Metabolsism still needs revising and memorizing, but for the first reading, it's ok, I guess. I read Goljan's high yield notes yesterday and they didn't seem rocket science anymore, started to make sense. I mean, I actually knew something. Questions though seem tricky. The whole picture is still a bit messy. Needs lot of work.

• point mutations
• missense mutations
• nonsense mutations
• deletion/insertion mutations
• framshift mutations

AD - autosome dominant (mostly structural protein defect) (gained/lost). E.g. Achondroplasia.

AR - autosomal recessive (usually ezyme defects) E.g. Cystic fibrosis.

X-linked inheritance. (From mother to son, no father to son) E.g. Hemophilia A.

X-linked dominant inheritance (more women affected).

Mitochondrial inheritance - (all children of a sick woman are affected; men don't transmit) Leber Herditary Optic Neuropathy