THE ICON PUBLIC

SCHOOL AHMEDNAGAR
INVESTIGATORY PROJECT
BIOLOGY
SUBMITTED IN FULFILMENT TOWARDS
CLASS 12 CBSE EXAMINATION
ACADEMIC YEAR 2024-25
ON THE TOPIC:
“GENETIC DISORDERS”
 THE ICON PUBLIC SCHOOL AHMEDNAGAR

DEPARTMENT OF BIOLOGY
CERTIFICATE
THIS IS TO CERTIFY THAT THE WORK ENTERED IN THE PROJECT
IS OF MISS AAFIA SAYYED OF GRADE 12
ROLL NO …………. EXAMINATION NO………………………….
HAS SATISFACTORILY COMPLETED THE REQUIRED AMOUNT OF
REASERCH AND WORKED TO PREPARE THE INVESTIGATORY
PROJECT OF THE ACADEMIC YEAR 2024-25

---------------- -------------------------- ------------------

HOD EXTERNAL EXAMINER INTERNAL EXAMINER
 ACKNOWLEDGEMENT

The success and the final outcome of the project required a lot
of guidance and assistance from many people. All I have done is
only due to supervision and assistance of my teachers.
I take this opportunity to express my profound gratitude and
deep regard to my teacher Ms.Anju for her exemplary guidance
and constant encouragement throughout the project.
I owe my deed and sincere gratitude to our principal Mrs.
Deepika Nagarwalla for providing us with great faculties and for
her cordial support.
I am also thankful to my parents and friends for their support
and encouragement ,which helped me in completing the
investigatory project
The guidance and support of my mentors ,principal and friends
has channelized my hard work ,energy and my thoughts to
attain this Investigatory project on the topic: “DNA
Fingerprinting”
 INDEX

Introduction 4

History 5

Mendelian disorder 6

Autosomal disorder 7

Huntington disorder 8

Autosomal recessive 9

Sickle cell Anemia 10

X- linked dominant disorder 11

X- linked recessive disorder 12

Color blindness 13

Diagnosis 14

Treatment 15

Conclusion 16

Bibliography 17
 INTRODUCTION

Genes are buildings block of heredity. They are passed from parents to child. They
hold DNA, the introduction for making proteins. Proteins do most of the work in
cells. They move molecules from one place to another, build structure, break
down toxins, and do many other maintenance jobs.
Sometimes there is a mutation, a change in a gene or gene’s. The mutation
changes the gene’s introductions for making a protein, so the protein does not
work properly or in missing entirely. This can cause a medical condition called a
genetic disorder
There are three types of genetic disorders:-
 Single-gene disorders, where a mutation affect one gene. Sickle cell anemia
is an example.
 Chromosomal disorders, where chromosomes (or parts of chromosome)
are missing or changed. Chromosomes are the structures that hold our
genes. Down syndrome is a chromosomal disorder
 Complex disorders, where there are mutation in two or more genes. Often
your lifestyle and environment also play a role. Colon cancer is an example.
Genetics test on blood and other tissue can identify genetic disorders.
 MENDELIAN DISORDERS
Mendelian or monogenic diseases are caused by mutation in one gene .They
run in families sometimes. Mendelian disorders are a result of a mutation at
a single genetic locus. This locus could be present on an auto some or a sex
chromosome. It can manifest itself in either dominant or recessive – mode.
A monogenic disorder is the result of a single mutated gene. Over 600
human diseases are caused by single gene defect. The division between
recessive and dominant types are not “hand and fast”, although the division
between autosomal and sex-linked types are distinguished purely based on
the chromosomal location of the year. For e.g.- , achandroplasia is typically
considered a dominant disorders, but children with two genes for
achondroplasia could be viewed as carrier. Sickel-cel anemia is also
considered a recessive condition, but heterogygousc carrier has increased
resistance to malaria in early childhood, which could be described as a
related dominant condition.
When a couple where are partners or both are sufferers or carrier of a single
gene disorders wish to have a child, they can do so through ‘In vitro
fertilization (IVF)’, which means they can have a pasimplatation genetic
diagnosis to check whether the embryo has the genetic disorders.
Most congenital metabolic disorders known as inborn errors of metabolism
result from single gene defect

AUTOSOMAL DOMINANT
Only one mutated copy of the gene will be necessary for a person to be affected by
an autosomal dominant disorders each affected person has one affected parents.
The chance a child will inherit the mutated gene is 50%. Autosomal dominant
condition sometimes have reduced penetrance, which means although only one
mutated copy is needed, not all individuals who inherit that individuals who inherit
that mutation go on to develop the disease. Examples of this type of disorder are
Huntington’s diseases, neurofibromatosis type I and II, Tuberous and will bran

 HUNTINGTON’S DISEASE
It is an autosomal dominant disorder. The disease appears after the age of 25
years. This is gradual loss of motor control due to deterioration of muscles and
brain. The brain shrikes to 20-30% of the original size. The symptoms begin with
uncontrolled shaking and jerky movements, followed by slurring of speech, Loss of
memories and hallucination. The frequency of this disease is one in fifth teen
thousand of living persons. The genotype of such patients has 42-100 repeats of
CAG nucleotides instead of the normal 10-30 repeats in chromosome 4.There is no
cure for this disorder. Full time care is required in the later stage of the disease.

AUTOSOMAL RECESSIVE
Autosomal recessive is one of several ways that a trait, Disease or disorder can be
passed down through families. An autosomal recessive disorder means two
copies of an abnormal gene must be present in order for the disease or trait to
develop .An affective person usually have an unaffected parents who each carry a
single copy of the mutated gene (and are referred to as carrier) . Two unaffected
people who each carry one copy of the mutated gene have a 25% risk with each
pregnancy of having a child affected by the disorder.

Example of this type of disease is: - Sickle cell anemia

Screening for many autosomal recessive diseases is available. You may get tested
if you have high odds of being a carrier of the disease, or if you just want to know
the risk of having a child with one of these diseases. A DNA test can check to see if
you and your partner carry any of the mutated genes that may cause your child to
have a disease. This can be done by taking a blood sample or gently scraping cells
from the inside of your mouth.
If you’re already pregnant, the health of your baby can be checked. Outpatient
procedures such as amniocentesis and chorionic villus sampling (CVS) check fluid
or tissue from your uterus to see if your baby shows signs of one of these diseases

 SICKLE CELL ANEMIA

It is an autosomal blood disorder caused by co-dominant alleles. The autosomal
mutant allele of normal hemoglobin gene is located on 11 th chromosome and
produces abnormal hemoglobin. It differs from the normal hemoglobin an in
oxygen caring capacity. Under low oxygen concentration, RBCs with hemoglobin S
become narrow and sickle shaped and clump together causing vascular
obstruction and serve anemia .The vital organ like liver and brain gets damaged
and lead to early death.
Symptoms:-
Pain in joint and cheats area
Whole body gets dizziness, fatigue low oxygen level in the body
Abnormal breakdown of red blood cells, inflamed fingers or toes, Pallor
Shortness of breath and yellow skin and eyes

X- Linked dominant disorder

X-linked dominant inheritance is a mode of genetic disorder by which a dominant
gene is carried on the X chromosome. As an inheritance pattern, it is less common
than the X-linked recessive type .In medicine, X- linked dominant inheritance
indicates that a gene responsible for a genetic disorder is located on the X
chromosome, and only one copy of the allele is sufficient to cause, someone who
expressed an X-linked dominant allele will exhibit the disorder and be consider
affected example- Goltz syndrome

 Goltz syndrome
Goltz syndrome is a rare genetic condition characterized by involvement of the
skin, skeletal system, eyes and face. Skin manifestation present at birth include the
skin and areas of missing skin; fat nodules in skin manifestation as soft, yellow-
pink nodules, and pigmentary
 X- Linked recessive disorder
X- Linked inheritance means that the gene causing the trait or the disorder is
located on the X chromosome. Female have two X chromosome; male have one X
and one Y. Genes on the X chromosome can be recessive or dominant. Their
expression in females and males is not the same.. X- Linked recessive gene is
expressed in female only if there are two copies of the gene (one on each X
chromosome. However, for males, there needs to be only one copy of an X-linked
recessive gene on order for trait or disorder to be expressed. For example, women
can carry a recessive gene on one of X chromosome unknowingly, and pass it on
to a son, who will express the trait:

 Colour blindness
Colour blindness is a X-linked recessive disorder. Some persons are unable to
distinguish certain colours. They are called colour blind person. Serial types of
colour blindness are known but the red-green colour blindness also called Daltons
is the most common.. It can impair task such as selecting ripe fruit, choosing
clothes and reading traffic light. Case 1 :- When a normal women marries to a
colour blind man, their offspring’s (Daughters and sons) will have normal colour
vision. But when these daughters are married to normal men 50% of their sons
will be colorblind and the remaining 50% will be normal, while daughters will all
be normal.Case 2 :- When a colour blind women is married to a normal men, their
daughters will be normal but all the sons will be colorblind . When these F1
daughters are married to colorblind men, colorblind sons and daughters will be
produced in equal numbers.
 Diagnosis
Due to the wide range of genetic disorder that is known, diagnosis is widely varied
and dependent of the disorder. Most genetic disorder are diagnosed at birth or
during early childhood however some, such on Huntington diseases, can escape
detection until the patient is well into adulthood.
The basic aspects of a genetic disorder rest on the inheritance of genetic material.
With an in-depth family history, it is possible to anticipate possible disorder in
children which direct medical professionals is to specific test depending upon the
disorder and allow parents the chance to prepare for potential life style changes,
anticipate the possibility of stillbirth, or contemplate termination parental
diagnosis can detect the presence of characterized substance via invasive
procedures which involve inserting probes or needles into the uterus such as in
amniocentesis.

Treatment
The treatment of genetic disorder is ongoing battle with over 1800 gene therapy
clinical trials having been completed, are going, or have been approved
worldwide. Despite this, most treatment options revolve around treating the
symptoms of the disorder in an attempt to improve patient quality of life.
Gene therapy refers to a form of treatment where a healthy gene is introduced to
a patient. This should alleviate the defects caused by a faulty gene or slow the
progression of disease a magion obstacle has been the delivery of genes to the
appropriate cell tissue and organ affected by the disorder.
 Conclusion
This project on “GENETIC DISORDER” is a very interesting project. This topic gives
us a lot of information about various types of genetic disorder. We have learned
that theme is lot of genetic disorder that can affect the human’s population. Not
all genetic disorder directly results in death; however there are no known cures
for genetic disorder. Many genetic disorder affect stages of development such as
Down syndrome, while others results in purely physical symptoms such as
muscular dystrophy. Others disorders such as Huntington disease, shows no sign
until adulthood Genetic disorders is a category of diseases that includes certain
types of birth defects, chronic diseases, developmental problems, and sensory
deficits that are inherited from one or both parents.
Those living with a genetic disorder, I want to remind you that you are not defined
by your condition. Though the challenges may sometimes feel overwhelming,
your strength, resilience, and ability to adapt are truly remarkable. Every person’s
journey is unique, and while the road ahead may have obstacles, it’s important to
remember that you are not alone. There is a vast network of support—family,
friends, medical professionals, and communities—that stand by you every step of
the way.
Science and medicine are advancing rapidly, and with every new discovery, new
treatments, and possibilities emerge. Hope is always on the horizon. You are not
defined by your diagnosis; you are defined by your spirit, your courage, and the
way you live your life. Seek support when you need it, take care of yourself, and
know that your voice matters in the ongoing efforts to understand, treat, and
ultimately cure genetic disorders.
 Bibliography
To complete this presentation, I have taken help from our
school biology book and I have collected information
from some Google sites. I have also taken the help of the
notes given by my biology teacher. The image attached in
this project is collected from internet.

LIST OF GOOGLE SITES ARE :-

 https://en.m.wikipedia.org
 https://www.genome.gov.com
 https://www.medicinenet.com
 https://rarediseases.info.nih.gov.com