2. WHAT IS A DISEASE?
A disease is an abnormal condition affecting the body of an organism. It is
often construed to be a medical condition associated with
specific symptoms and signs.
TYPES OF DISEASES
Pathogenic Deficiency Hereditary Physiological
disease disease diseases disease
Polygenic Monogenic Chromosomal
disorders disorders aberrations
3. WHAT IS A GENETIC DISEASE?
• It is a disorder caused by genetic factors and especially
abnormalities in the human genetic material (genome).
There are four main types of genetic disorders. Of
course, some of these changes in genome can cause
interesting advantages in specific environments
(Darwinian Fitness). But there is no doubt that all these
abnormalities (disorders) bring destructive results to a
living being in the present environment.
• There are three types (human) of genetic diseases are:
5. 1) MULTIFACTORIAL / POLYGONIC GENETIC
DISEASES:
• The second type of human genetic diseases is caused
by mutations in more than one genes.
• The environment combines with these mutations in
order these diseases to appear.
• We can easily conclude that polygenic disorders are
more complicated than the previous type (single
gene diseases). These abnormalities are also difficult
to analyze, because there are many factors that
researchers should take into consideration in order
to reach to some useful conclusions.
• Many well known chronic diseases are Multifactorial
Genetic Diseases. Everybody knows
Alzheimer, diabetes, obesity and arthritis. Besides
many cancer types are caused by multi mutations.
6. OBESITY
• Obesity is a medical condition in which excess body fat has accumulated
to the extent that it may have an adverse effect on health, leading to
reduced life expectancy and/or increased health problems. Body mass
index (BMI), a measurement which compares weight and height, defines
people as overweight (pre-obese) if their BMI is between 25 and
30 kg/m2, and obese when it is greater than 30 kg/m2.
• Obesity increases the likelihood of various diseases, particularly heart
disease, type 2 diabetes, obstructive sleep apnea, certain types
of cancer, and osteoarthritis .
• Obesity is most commonly caused by a combination of excessive food
energy intake, lack of physical activity, and genetic susceptibility, although
a few cases are caused primarily
by genes, endocrine disorders, medications or psychiatric illness. Evidence
to support the view that some obese people eat little yet gain weight due
to a slow metabolism is limited; on average obese people have a greater
energy expenditure than their thin counterparts due to the energy
required to maintain an increased body mass
8. 2) SINGLE-GENE/MONOGENIC GENETIC
DISEASES:
In this category the starting point is a mutation/change in
one gene.
• How a change in the sequence of a single gene can cause
severe disorders?
• Genes code for proteins which are some of the most
important tools for the living beings, and also take place in
the structures of the cells. The results of a mutation that
happens in a part of gene that codes for a functional part of
a protein are unwelcome. The protein is no more functional
and as a result, many severe consequences take place.
• Almost 6000 single gene disorders are known and it is
estimated that 1 of 200 newborns face a single gene
genetic disorder. Some of these are sickle cell
anemia, cystic fibrosis, Aicardi Syndrome, Huntington’s
disease.
9. SICKLE CELL DISEASE
Sickle-cell disease (SCD), recessive genetic blood disorder with
over dominance, characterized by red blood cells that assume
an abnormal, rigid, sickle shape. Sickling decreases the cells'
flexibility and results in a risk of various complications. The
sickling occurs because of a mutation in the hemoglobin gene.
Sickle-cell disease may lead to various acute and chronic
complications, several of which have a high mortality rate.
Sickle cell disease is prevalent in many parts of India, where
the prevalence has ranged from 9.4 to 22.2% in endemic areas.
Blood transfusions are often used in the management of sickle
cell disease in acute cases and to prevent complications by
decreasing the number of red blood cells (RBC) that can sickle
by adding normal red blood cells.
11. 3) CHROMOSOMAL GENETIC DISEASES:
• Chromosomes are big DNA molecules composed from
genes. The chromosomes are located in the cell nucleus.
• Abnormalities in the structure, number (and not only) of
the chromosomes can cause some of the most dangerous
genetic disorders.
• This type of disorders seem to be much easier to observe
because they are, sometimes, detected by examination
with microscope.
• Down Syndrome is the most well known disease caused by
chromosomal abnormalities. In this disorder there is a third
copy of chromosome 21 (there are two copies of each
chromosome in the cells of healthy humans). Chromosomal
diseases can be also caused by segments and joins of parts
of chromosomes.
12. DOWN SYNDROME
• Down syndrome, or Down's syndrome is a chromosomal condition caused by the
presence of all or part of an extra Down syndrome is a chromosomal condition
characterized by the presence of an extra copy of genetic material on the 21st
chromosome, either in whole (trisomy 21) or part (such as due to translocations). The
effects and extent of the extra copy vary greatly among people, depending on genetic
history, and pure chance.
• Individuals with Down syndrome may have some or all of the following physical
characteristics: microgenia (an abnormally small chin), an unusually round
face, macroglossia (protruding or oversized tongue), an almond shape to the eyes
caused by an epicanthic fold of the eyelid, upslanting palpebral fissures(the separation
between the upper and lower eyelids), shorter limbs, a single transverse palmar
crease (a single instead of a double crease across one or both palms), poor muscle
tone, and a larger than normal space between the big and second toes. Health concerns
for individuals with Down syndrome include a higher risk for congenital heart
defects, gastroesophageal reflux disease, recurrent ear infections that may lead to
hearing loss, obstructive sleep apnea, thyroid dysfunctions, and obesity.
• 21st chromosome
14. WILSON’S DISEASE
Wilson's disease is an recessive genetic disorder in which copper
accumulates in tissues; this manifests as neurological or
psychiatric symptoms and liver disease. It is treated with
medication that reduces copper absorption or removes the
excess copper from the body, but occasionally a liver transplant is
required. Liver disease may present as tiredness, increased
bleeding tendency or confusion.
In general, a diet low in copper-containing foods is
recommended, with the avoidance of mushrooms, nuts and
chocolates. Various treatments are available for Wilson's disease.
Some increase the removal of copper from the body, while others
prevent the absorption of copper from the diet.
15. AUTOSOMAL RECESSIVE
• majority of mendelian disorders
• only homozygotes are affected, heterozygotes
(parents) are only carriers
• 25% of descendants are affected
• if the mutant gene occurs with low frequency -
high probability in consanguineous marriages
• onset of symptoms often in childhood
• frequently enzymatic defect
• testing of parents and amnial cells.
16.
17. PREVENTION
• Many diseases and disorders can be prevented through a
variety of means. These
include sanitation, proper nutrition, adequate exercise, vac
cinations.
A prevention or preventive therapy is a way to avoid an
injury, sickness, or disease in the first place. A treatment
or cure is applied after a medical problem has already
started. A treatment attempts to improve or remove a
problem, but treatments may not produce permanent
cures, especially in chronic diseases.
18. TREATMENT
• Medical therapies or treatments are efforts to cure or improve a
disease or other health problem. In the medical field, therapy is
synonymous with the word "treatment". Among psychologists, the
term may refer specifically to psychotherapy or "talk therapy".
Common treatments include medications, surgery, medical
devices, and self-care. Treatments may be provided by an
organized health care system, or informally, by the patient or family
members.
• Treatment for medical emergencies must be provided promptly, often
through an emergency department or, in less critical
situations, through an urgent care facility.
• self-care and public health measures.
19.
20. MADE BY:
ESHLEEN WALIA (12)
SIMRAN UPPAL(29)
MANVI GUPTA(14)
SHRADDHA S. MOHANTY(28)
AKSHITA GARG(4)
X/D
