This document discusses hemophilia, an X-linked recessive bleeding disorder caused by deficiencies in coagulation factors VIII or IX. It describes the types of hemophilia, including Hemophilia A, B, and C. It also covers inheritance patterns for hemophilia and probabilities for offspring. Additionally, it discusses red-green color blindness as another X-linked recessive trait, describing the types and inheritance.

1. Inheritance biology
PRESENTED BY S . PALANI ANANTH
PRESENTEDTO DR . K .NALINI

2. What is Hemophilia?
▪ “Hemophilia is a common hereditary coagulation blood disorder due to deficiency or reduced
activity of clotting factorVIII or clotting factor IX.
▪ This disorder is a X- linked recessive disorder.
▪ Hemophilia is a bleeding disorder that slows down the blood clotting process.
▪ It’s transmitted via females to men who are sufferers.
▪ Female who carry a single mutated gene, are generally asymptomatic and not affected.
▪ People who have Hemophilia often have longer bleeding after some sort of contact to injury.
People who have severe Hemophilia start to have spontaneous bleeding in the joints and
muscles all around their bodies.
▪ Hemophilia is more common in males than females.

3. COAGULATION FACTORS
Factor I – Fibrinogen
• Factor II - Prothrombin
• Factor III –Tissue factor (TissueThromboplastin)
• Factor IV – Calcium
• FactorV – Labile factor (Proaccelerin)
• FactorVII – Serum Prothrombin Conversion
Accelerator (SPCA)
• FactorVIII – Anti-Hemophilic Factor
• Factor IX – PartialThromboplastin Component (PTC);
Christmas Factor
• Factor X – Stuart-Prower Factor
• Factor XI – Plasma
Thromboplastin Antecedent (PTA)
• Factor XII – Hagemann factor
• Factor XIII – Fibrin stabilizing
Factor

4. ▪ Originally termed “Haemorraphilia” i.e. love for hemorrhage's ( love of bleeding).
▪ Its also called queenVictoria disease.
TYPES: Hemophilia A Hemophilia B Hemophilia C
▪ Hemophilia A is an X-linked genetic disorder involving a lack of functional clotting Factor
VIII and represents 90% of hemophilia cases.
▪ Hemophilia B is an X-linked genetic disorder involving a lack of functional clotting Factor IX It
is more severe but less common than Hemophilia A.
▪ Hemophilia C is an autosomal recessive genetic disorder involving a lack of functional
clotting Factor XI. (Autosomal recessive)
▪ PARA HEMOPHILIA : factorV deficiency is also called owren’s disease (Autosomal recessive)

5. SUMS
▪ A man with hemophilia (a recessive, sex-linked blood clotting disorder) has a daughter of
normal phenotype. She marries a man who is normal for the trait. X H - normaL
X h - hemophilia.
▪ Since this is a recessive disorder, one X H allele will give a normal phenotype. When the
offspring do not have a X H and only have the X h allele/alleles they will have the
hemophilia condition.
▪ Man’s genotype is X hY. Daughter’s genotype is X H X h (She got the X h from her
father. She has a normal phenotype, so we know her other allele is X H
▪ Daughter’s Husband is X HY (Man is normal for the hemophilia trait).

6. A)What is the probability that a daughter of this mating with be a hemophilic
▪ The probability that a daughter of this mating with be a hemophiliac is zero.
B) If the couple has four sons, what is the probability that all four will be born with hemophilia.
▪ Each occurrence has a 1/2 chance of happening.
▪ The probability that all 4 sons have inherited hemophilia would be 1/2 x 1/2 x 1/2 x 1/2 =
1/16= 6.25%
XH Xh
XH XH XH XHXh
Y XHY XhY

7. Red-Green Color-Blindness
▪ An inability to differentiate between red and green. Seeing other colors in place of green.
▪ Inherited condition maybe due to following
▪ In our eye there are two types of light sensitive cell
1. Rods 2. cones
▪ Both found in retina which is a layer at the back of eye it processes images.
▪ The rods are responsible for vision in night as work in low light condition ( cannot
distinguish different wavelength of light)
▪ The cones are responsible for color discrimination.

8. Red-Green Color-Blindness
▪ there are three types of cones
▪ ( differ on the basis of photoreceptor protein they make)
1. L-cones sense long wavelength ( red light)
2. M-cones sense medium wavelength ( green light)
3. S-cones sense shorter wavelength ( blue light )

9. Red-Green Color-Blindness
▪ There are 4 types of red-green color blindness:
▪ Deuteranomaly is the most common type of red-green color blindness. It makes green look
more red.This type is mild and doesn’t usually get in the way of normal activities.
▪ Protanomaly makes red look more green and less bright.This type is mild and usually
doesn’t get in the way of normal activities.
▪ Protanopia and deuteranopia both make you unable to tell the difference between red
and green at all

10. Red-Green Color-Blindness

11. Red-Green Color-Blindness
▪ Red-green color blindness is caused by a sex-linked recessive allele. A color-blind man
marries a woman with normal vision whose father was color-blind. note: I changed the
wording of this question.
▪ Man X bY Woman X B X b . We know this because she has normal vision (X B ). Her father
was color-blind and gave her X b allele
1) What is the probability that their daughter will be color-blind?
note: Because they are telling you in the problem that there is a daughter, you do not have to
figure in the probability that the child will be a girl.

12. Red-Green Color-Blindness
XB Xb
Xb XBXb XbXb
Y XBY XbY
• The chance that she will be color-blind is 1/2. OR 50%
2)What is the probability that their son will be color- blind?
note: Because they are telling you in the problem that there is a son, you do not have to
figure in the probability that the child will be a boy.
 The chance that a son will be color-blind is also ½ OR 50%