Interesting information about human genetics

2. INHERITANCE AND HUMAN VARIATION
People are different from each other because:
Genetic differences: each people (except identical twins) has their own exclusive genotype
Environmental factors: such as food or lifestyle. They are not transmitted in the phenotype.
TYPES OF TRAITS
Quantitive traits
Qualitive traits
Hair
Eye colour
Skin colour
Determined by a pair of alleles
There are dominant or recessive traits
The blood groups The Rh system

3. GENETIC STUDIES IN HUMANS
HUMAN KARYOTYPE ESTUDIES
They let us to make a comparison between the chromosomes of individuals and the species
standard chromosome pattern.
It helps to detect chromosome anomalies.
DIAGNOSIS OF GENETIC DISEASES
Symptons of genetic disease can be treated.
Some genetic diseases can be prevented if they are detected early enough.
It is important to detect them before birth using the amniocentesis.
CONGENITAL MALFORMATIONS
They are the alterations in the shape, structure or sixe occurred during foetal development.
It can be caused by: genetic alterations, envirnmental factors (radiation...) or infectious diseases.
Examples: lims, the cleft palate, alterations in heart or liver, cataracts, deafness.
Some of them can be detected using ultrasound testing.

4. HUMAN GENETIC DISORDERS
AUTOSOMAL DISORDERS
PATTERN:
ONE OF THE PARENTS HAS TO HAVE THE DISORDER
DISORDERS
Dwarfism
Polydactylism
Hypertension
THE PARENTS DON’T NEED TO SUFFER
D
O
M
I
N
A
N
T
RECCESIVE
Albinism

5. SEX LINKED DISORDERS
LINKED TO X CHROMOSOME
LINKED TO Y CHROMOSOME
Hypertrichosis Ichtyosis
Colour blindness
(daltonism)
Haemophilia

6. DISORDERS RELATED TO
CHROMOSOME NUMBER
AUTOSOMAL DISORDERS
Down syndrome

7. SEX CHROMOSOME DISORDERS
DISORDERS THAT AFFECT WOMEN
DISORDERS THAT AFFECT MEN
Triple X syndrome
• Mild learning disabilities
• Delayed development of speech and motor skills
 Turner syndrome
• Sterility
• Short height
 XYY syndrome
• Skeleton malformations
• Mild to moderate learning disabilities and aggressiveness
 Klinefelter syndrome
• Small genitals and sterility in some cases
• Mild learning disabilities

8. CHANGES IN CHROMOSOME STRUCTURE
DELETION:
When a piece of chromosome is missing.
It causes animalies in the skeleton and intellectual disabilities.
Example: Cri-du-chat syndrome
DUPLICATION:
When a part of chromosome is repeated.
INVERSION:
When a piece of chromosome is reversed.
TRANSLOCATION:
When a piece of chromosome becomes attached to a different chromosome.
Example: Chronic Myelogenous Leukaemia (CML).