Lecture 17 - QF PCR Flashcards
What is aneuploidy
the gain or loss of a chromosome
What is monosomy
the loss of a chromosome
What is disomy
two copies of a chromosome
What is trisomy
three copies of a chromosome
What is non-disjunction
the failure of one or more pairs of homologous chromosomes to separate normally during nuclear division resulting in an abnormal distribution of chromosomes
What is turner syndrome
- 45 , X
- caused by paternal non-disjunction
What is the frequency of turner syndrome
1 in 2500 newborn girls
What is the phenotype of turner syndrome
-short stature
-webbed neck
-low hairline
-loss of ovarian function
-cardiac defects
-kidney disease
-normal intelligence
What is klinefelter syndrome
- 47, XXY
- caused by paternal and maternal non-disjunction
What is the phenotype of klinefelter syndrome
- tall with long limbs
- small testes and penis
- breast growth
- decrease sexual interest
- lower than average intellignece
what is the frequency of klinefelter syndrome
1/650 newborn boys in the US
1-2/1000 live male births in the UK
What is trisomy X
- 47, XXX
- caused by maternal non-disjunction
What is the phenotype of trisomy X
- taller than average
- developmental delays
What is the frequency of trisomy X
1/1000 female births in canada and the us
What is Jacob syndrome
- 47, XYY
- caused by paternal non-disjunction or post-zygotic cleavage errors
What is the phenotype of Jacob syndrome
- tall
- enlarged head
- anti-social
- learning disabiliities
- usually fertile
What is the frequency of jacob syndrome
1 in 1000 live male births
What is patau syndrome
- 47, XX+13 or 47, XY+13
- caused by non-disjunction of either parent
What is the phenotype of patau syndrome
- small eyes
- extra digits
- cleft palate
- heart and CNS defects
What is the frequency of patau syndrome
1/16 000 newborns
~90% of infants die within a year
What is edwards syndrome
- 47, XX+18 or 47, XY+18
- caused by maternal non-disjunction
What is the phenotype of edwards syndrome
- small, long head
- small mouth
- underweight
- feeding and breathing problems
- heart and genitorinary issues
- severe cognitive impairment
What is the frequency of edwards syndrome
1/5000 newborns
~90% of infants die within a year
What is downs syndrome
- 47, XX+21 or 47, XY+21
- caused by maternal non-disjunction
