Pedigree charts
Presented by:- Simardeep Bathan (81)
Smayera Sood(82)
Objectives
Diseases
Defination of Different types related
pedigree of inheritance inheritances
charts,its
importance
and its uses
Pedigree charts
Padigree is a family tree
diagram that helps
identify how a genetic
disorder or trate is passed
down from one generation
to the next.
P
e Determine inheritance pattern
d
i
g Identify carriers of genetic
r condition
e
e Predict risk for future
C
h
a Tool for genetic counselling
r
t
s
Male
Identical twins
Female
Marriage Fraternal twins, female
Continuous Affected male and female
marriage
Affected by history, male
and female
Carrier
Disease, male and female
Sex unspecified
Types of Inheritance
Multifactorial
inheritance,
Single gene
inheritance
Single Gene Inheritance
X-linked
Y-linked
Autosomal
Dominant Recessive Dominant Recessive
Autosomal Inheritance
Autosomal Dominant
The gene responsible for this kind of
trade is present on auto and can
manifest the disorder, even if it is in
single dose
The muted gene is present on one
chromosome of the pair
Exceptions
ABO blood grouping
Sex Limited trades
Sex influence trades
Pelotropy
Some common autosomal dominant
disorders
Huntington Chorea
Myotonic dystrophy
Achondroplasia
Neurofibromatosis
Myotonic Dystrophy
Incidence one in 8000 people
Clinical features
Patient suffers from progressive weakness and myotonia
Disturb gastrointestinal peristalsis
Genetics
It is Autosomal Dominant Disorder with anticipation
This gene is located on the long arm of chromosome number 19
This gene is responsible for the Synthesis of Myotonic Dystrophy
Protein Kinase(MDPK)
Autosomal recessive inheritance
For expression of the straight, the gene should be in
homozygous state double Dose
Heterozygous individuals are normal.
This rate is seen insane generation among brothers
and sisters siblings
Males and females are equally affected
Autosomal recessive disorders
Albinism
Phenylketonuria
Alkaptonuria
Spinal muscular trophy
Sickle cell anaemia
Schizophrenia
Cystic fibrosis
Cystic Fibrosis(Mucoviscidosis)
Incidence: 1 in 2500 people in population
It is the most common series disorder seen in the children of white
population of Europe
Genetics
Cystic fibrosis shows autosomal recessive inheritance
The gene of CF is present on the long arm of chromosome number
7
X linked inheritance
X-Linked Recessive
Some of the genes on X chromosomes are functionally similar to the
genes present on the autosomes.
Females have 2X chromosomes while male have only one.
Predominantly males are affected This disorder is transmitted through
unaffected carrier females to their sons.
Defective males cannot transmit the disorder to their sons as the gene
is not present in white chromosome
Some common X linked recessive disorders
Duchenne Muscular Dystrophy
Haemophilia
Haemophilia
Haemophilia is an inherited coagulation disorder
Incidence:
Haemophilia A : 1 in 5000 males. Haemophilia B: 1 in 40,000
males.
Haemophilia shows an X linked recessive inheritance
Genes for Haemophilia A and B are located on the long arm of X
chromosome near its distant
X-Linked Dominant Inheritance.
It expresses in Heterozygous females as well as in
males.
The X linked dominant inheritance resembles that
of an autosomal dominant inheritance, but can be
differentiated because of the fact that an affected
male transmit this straight to all his daughters but
to none of his sons.
X-Linked Dominant Disorders
Vitamin D resistant rickets
XG blood groups
Hypophosphatemia
Y-Linked Inheritance
Males of all generations are affected
revealing that the gene is transferred by
males to males.
Males transmit SRY/TDF (and their Y chromo-
some) to all of their sons, but not to their
daughters.
Thank you
