Inherited disorders

inherited disorders

1. InherIted dIsorders
Prof. H. S. Shinde
K. K. Wagh College of Agricultural Biotechnology, Nashik. India

2. Inherited disorder
Defination- Inherited disorder or genetic disorder is a disease that is
caused by an abnormality in an individual's DNA. Abnormalities can
range from a small mutation in DNA or addition or subtraction of an
entire chromosome or set of chromosomes.
Most inherited disorders are quite rare and affect one person in every
several thousands or millions.
Inherited disorders may results by
•Point mutation, or any insertion/deletion entirely inside one gene
•Deletion of a gene or genes
•Whole chromosome extra, missing, or both

3. Allosomal Disorders
•Allosomes are also referred to as sex chromosomessex chromosomes
•Inherited disorders which are related to sex chromosomes are
called as Allosomal disorders
•Examples of allosomal disorder are
1.Kleinfelter’s syndrome
2. Turners syndrome

4. Kleinfelter’s syndrome
(or Klinefleter’s)
Disorder occurring due to nondisjunction of the X chromosome.
The Sperm containing both X and Y combines with an egg containing the
X, results in a male child.
The egg may contribute the extra X chromosome.

5. XXY
•Males with some development of breast tissue.
•Little body hair is present, and such person are typically tall, have small
testes.
• Infertility results from absent sperm.
•Evidence of mental retardation may or may not be present.

7. Turner’s Syndrome
•Due to monosomy X- (absence of an entire sex chromosome)
•Turner syndrome is associated with underdeveloped ovaries, short stature,
webbed, and is only in women
•Broad chest.
•Individuals are sterile, and lack expected secondary sexual characteristics.
• Mental retardation typically not evident.

8. Turner’s Syndrome

9. Autosomal disorders
•An autosome is a chromosome that is not an allosome (i.e.,
not a sex chromosome).
•Autosomes appear in pairs
•humans have a diploid genome that usually contains 22 pairs
of autosomes and one allosome pair (46 chromosomes total).
•Disorders related to Autosome are autosomal disorders

10. •Examples of Autosomal disorder
1. Downs syndrome
2. Haemophilia
3. Sickle cell anemia

11. Down’s Syndrome
Caused by non-
disjunction of the 21
st

chromosome.
This means that the
individual has a
trisomy (3 – 2lst
chromosomes).

12. Down’s Syndrome
or Trisomy 21

13. Symptoms of Down Syndrome
•Small ears that fold over at the top.
•Small, flattened nose.
•Small mouth, making tongue appear large.
•Short neck.
•Small hands with short fingers.
•Mental retardation

14. Haemophilia
•Haemophilia is a hereditary genetic disorders that impair the
body's ability to control blood clotting or coagulation
•Blood clotting or coagulation is useful to stop bleeding when
a blood vessel is broken.
•Haemophilia A (clotting factor VIII deficiency) is the most
common form of the disorder, present in about 1 in 5,000–
10,000 male births.
• Haemophilia B (factor IX deficiency) occurs in around 1 in
about 20,000–34,000 male births.

15. •Haemophilia A and B both are recessive X-linked genetic
disorder
•Symptoms- uncontrolled bleeding without any control after
wound

16. Sickle Cell Anemia
Occurs due to mutation in
the haemoglobin gene.
An inherited, chronic disease
in which the red blood cells,
normally disc-shaped
As a result, they function
abnormally and cause small
blood clots.

17. Sickle Cell Anemia
Sickle cell disease is most commonly found in African and
American populations.
 This disease was discovered over 80 years ago

18. Other examples

19. Color Blindness
Cause: X-linked recessive
The genes that produce
photopigments are carried on
the X chromosome; if some
of these genes are missing or
damaged, color blindness
will be expressed in males
with a higher probability
than in females
Individuals are unable to
distinguish shades of red-
green.

21. Albinism
•Due to absence or defect of tyrosinase, a copper-containing enzyme
involved in the production of melanin.
•Albinism results from inheritance of recessive gene alleles and is known to
affect all vertebrates
•Patients are unable to
produce skin or eye
pigments, and thus
are light-sensitive

22. Hairy ears
Y-linked trait, which
is rare
Symptoms…hairy ears