lesson 4 chromosomal anomalies
TRANSCRIPT
What happens if the number of chromosomes is not 46 in a human being?
To what extent can genetics influence who you end up being?
Number or Structure
Not all chromosomal abnormalities are compatible with life.
Those abnormalities that are compatible with life, cause signs symptoms in the individuals that suffer them.
The group of signs and symptoms related to a known genetic disorder is named as a Syndrome.
The chromosomal anomalies maybe in number or in structure.
Numerical Abnormality: an abnormal number of chromosomes.
When an individual is missing either a chromosome from a pair (monosomy) or has more than two chromosomes of a pair (trisomy)
Structural Abnormality: when the structure of the chromosome is changed.
Deletions
Duplications
Translocations
Inversions
Rigns
Source: National Human Genome Research Institute
Why do they happen?
Errors in cell division (mitosis or meiosis)
Monosomy:
X Turner Syndrome 45, XO
Trisomy:
21 Down Syndrome 47,XX or XY, +21
18 Edwards Syndrome 47, XX or XY ,+18
13 Patau Syndrome 47, XX or XY, +13
XXY Klinefelter Syndrome 47,XY,+X
XXX Triple X Syndrome 47,XX, +X
Deletions
Duplications
Translocations
Inversions
Rings
Amniocentesis
Karyotyping
Have fetus DNA
Male or female?
Chromosome number:
Abnormality?
Numerical or Structural?
What type?
Male or female?
Chromosome number:
Abnormality?
Numerical or Structural?
What type?
Male or female?
Chromosome number:
Abnormality?
Numerical or Structural?
What type?
Source: Indian Journal of Human Genetics
Linda Hunt: 45,XO
In groups of 4
Time: 40 min.
You are given a set of chromosomes extracted from a human cell in metaphase.
You must first make the karyotype, by cutting and organizing the chromosomes with the help of an ideogram.
With the finished karyotype: Diagnose
Make a short presentation (1 or 2 slides) of your diagnosis. Support your information with scientific facts. Chromosome number
Gender of the individual
Chromosomal abnormality? Healthy?
Type of chromosomal abnormality?
Main signs and symptoms
Frequency in the Spanish population
Ideogram
Set of chromosomes
Karyotype template