Complete Mnemonic Collection for GEN-02
1. Chromosomal Disorder Karyotypes — "DTK-Super"
- Down = Trisomy 21 (47, +21) → "Down Tri-21 down the stairs"
- Turner = XO (45, XO) → "Turner turned off one X"
- Klinefelter = XXY (47, XXY) → "K-line has eXtra X but Y makes him male"
- Super Female = XXX (47, XXX) → "Super has three X's, often fine"
2. X-Linked Recessive Father Rule — "Dad Never Sends X to Son" Father passes D-ad's → Never → Sends → X to Son = "Dad gives Y to son, always." Consequence: haemophilia in sons comes from MOTHER, not father.
3. Sickle Cell Mutation — "GAG to GUG, Glu to Val, 6th position"
- Normal codon 6: GAG = Glutamic Acid (Good blood)
- Sick codon 6: GUG = Valine (Vasco-occlusion)
- Memory: "GAG becomes GUG and the blood cells GUG (gug = )"
4. Sex Determination Heterogametic Sex — "HuMans Male; BiRds Female"
- HuMans (Male heterogametic) → XX-XY system
- BiRds (Female = ZW heterogametic) → ZW-ZZ system
- Remember "R" for Reverse → birds are the REVERSE of humans
5. Thalassemia Chromosomes — "ALPHA 16, BETA 11" A16pha — alpha = 16 (A is the 1st letter, 16 is the smaller chromosome pair) B11eta — beta = 11 (B is the 2nd letter; beta-globin on chromosome 11, same as sickle cell)
6. Gene Locations Quick Fire — "PAH on 12, HBB on 11, HBA on 16, F8 on X"
- PKU → PAH → chromosome 12 ("PKU — twelve letters helps = no, just remember P-A-H-12")
- Sickle / Beta-thal → HBB → chromosome 11 ("Sickle-Eleven, HBB-Eleven")
- Alpha-thal → HBA → chromosome 16
- Haemophilia A → F8 → X chromosome
7. Carrier to Affected Rule — "Carrier Mom, Affected Son; Affected Dad, Carrier Daughter" This criss-cross inheritance pattern tells you exactly where X-linked alleles travel: Maternal line: carrier mother → 50% of sons affected Paternal line: affected father → all daughters become carriers