Genetic disordors and their classification, single gene inheritance, multifaction inheritance, mitochondrial inheritance and the chromosomal inheritance

1. CLASSIFICATION OF GENETIC
DISEASE
BY WAKIB AMIN MAZUMDER, 82B

2.  A genetic disorder is a genetic problem caused by
one or more abnormalities in an individual's
genome, especially a condition that is present from
birth (congenital). Most genetic disorders are quite
rare and affect one person in every several
thousands or millions.
 The human genome is the entire "treasury of
human inheritance." The sequence of the human
genome obtained by the Human Genome Project,
completed in April 2003, provides the first holistic
view of our genetic heritage.
 Gene - The basic unit of heredity.
 Genome-Total genetic information encoded in a
cell.

3. Classification of Genetic Disease:
 Single gene inheritance
 Single gene inheritance, also called
Mendelian or monogenetic inheritance.
This type of inheritance is caused by
changes or mutations that occur in the
DNA sequence of a single gene. which
occur in about 1 out of every 200 births.
30%
 Ex-Sickle cell anemia

4.  Multifactorial inheritance-
 It is also called complex or polygenic
inheritance. Multifactorial inheritance
disorders are caused by a combination
of environmental factors and mutations
in multiple genes. 55%
 Ex-Cancer

5.  Mitochondrial inheritance
 This type of genetic disorder is caused
by mutations in the non- nuclear DNA
of mitochondria. Mitochondria are small
round or rod- like organelles that are
involved in cellular respiration and
found in the cytoplasm of plant and
animal cells.
 Ex-an eye disease called Leber's

6.  Chromosome abnormalities
 Chromosomes, distinct structures made up
of DNA and protein, are located in the
nucleus of each cell. Because
chromosomes are the carriers of the
genetic material, abnormalities in
chromosome number or structure can
result in disease. Abnormalities in
chromosomes typically occur due to a
problem with cell division.15%
 Down syndrome,(47)Turner syndrome,
(45,X0), &Klinefelter Syndrome(47, XXY)