CYTO 11 & 12

• CHROMOSOMAL ABNORMALITIES - these alteration can be detected by studying the affected person's karyotype
• 2 basic groups of chromosomal abnomalities: Numerical & Structural Abnomalities
• CELL DIVISION - one of the most important activities that cells undergo
• • KARYOTYPE - displays all chromosomes in a cell
• NUMERICAL ABNORMALITIES - there are changes in the number of chromosomes of a karyotype
• ANEUPLOIDY - loss or gain of 1 or more chromosome
• POLYPLOIDY - addition of 1 or more complete haploid chromosome
• MONOSOMY - loss of single chromosome
• TRISOMY - gain of 1 or more homologous chromosome
• NULLISOMIC GAMETES - no chromosomal material
• TURNER SYNDROME - aka 45, X Karyotype
• TURNER'S SYNDROME - aka Monosomy X, there is one chromosome & no second sex chromosomes
• Turner's syndrome - is a disorder affecting women
• Turner's Syndrome frequency is 1/ 2500 births
• TRISOMY - presence of an extra chromosome
• DOWN SYNDROME often known as Trisomy 21
• XXY aka Klinefelter's Syndrome
• Klinefelter's Syndrome (XXY) is a disorder affecting men
• KLINEFELTER'S SYNDROME - 2 X chromosomes & one Y chromosome
• Klinefelter's Syndrome frequency is 1/500 - 600 males
• XXX - triple X syndrome
• Triple X Syndrome is a disorder afecting women
• Triple X chromosome frequence is 1/1000 girls
• XYY Syndrome - Supermale Syndrome or JAcob Syndrome
• XYY Syndrome is a disorder affecting men
• XYY SYNDROME OR SUPERMALE SYNDROME - one X chromosome & 2 YY in pair 23
• XYY Syndrome frequency is 1/1000 males
• DOWN'S SYNDROME - 3 chromosomes in pair 21
• Down's syndrome frequency is 1/600 - 800 infants
• Down's syndrome average lifespan is 60 years
• EDWARD'S SYNDROME - 3 chromosomes in pair 18
• Edward's Syndrome frequency is 1/5000 - 8000
• PATAU'S SYNDROME - 3 chromosomes in pair 13
• Patau's Syndrome frequency is 1 in 10,000 to 15,000 live births
• STRUCTURAL ABNORMALITIES - result from chromosome breakage with subsequent reunion in a different configuration
• Structural abmormalities can be balance or unbalance
• BALANCED REARRANGEMENTS - chromosome complement is complete
• UNBALANCED REARRANGEMENT - chromosomal complement contains an incorrect amount of chromosome material
• TRANSLOCATIONS - portion of one chromosome is transferred to another chromosome
• 2 types of Translocations: Reciprocal Translocation & Robertsonian Translocation