Haemophilia

Haemophilia

Subject: Science & tech

Section: Basic science

Context- Every year, World Haemophilia Day is observed on April 17 to increase awareness of haemophilia and other bleeding disorders, in order to ensure better diagnosis and better access to care for the millions who remain without treatment.

Concept-

• This year, the theme for World Haemophilia Day is “Access for All: Partnership. Policy. Progress. Engaging your government, integrating inherited bleeding disorders into national policy”.

What Is Haemophilia?

• Haemophilia is usually an inherited bleeding disorder in which the blood does not clot properly, which can lead to spontaneous bleeding as well as bleeding following injuries or surgery.
• Several proteins are present in the blood which can help stop bleeding. These proteins are called clotting factors.
• Haemophilia is a sex-linked recessive disease. Therefore, it shows transmission from an unaffected carrier female (heterozygous individual) to some of the male progeny. A single cut in the affected individual will result in non-stop bleeding.
• Due to the presence of defective forms of blood clotting factors, the exposed blood of affected individuals fails to coagulate.

Sex Linked Disease:

• The sex of an individual is determined by a pair of “sex chromosomes” (a chromosome is a DNA molecule that contains genetic information).
• Females are identified with an XX pair of sex chromosomes, and males with an XY pair.
• When an X chromosome from the mother pairs up with the father’s X chromosome, the offspring is XX (female); when an X chromosome from the mother pairs up with the father’s Y chromosome, the offspring in XY (male).
• Haemophilia is caused by a defect in the X chromosome. If a girl is born with one defective X chromosome, her other X chromosome can compensate for it. In such a case, she is a carrier of haemophilia but will not suffer from the condition herself. Only if both her X chromosomes are defective will she suffer from haemophilia herself.
• On the other hand, if a boy is born with a defective X chromosome, he does not have the second X chromosome to compensate for it, and will suffer from haemophilia.
• That is the reason haemophilia is more common among men.
• The possibility of a female becoming haemophilic is extremely rare because the mother of that individual has to be at least a carrier, and the father should be haemophilic.
• This is rarely possible because a haemophilic male becomes unviable in the later stage of his life. Also, a haemophilic female dies before birth.

Types Of Haemophilia

• There are several types of haemophilia.
• The two most common forms of the disease are Haemophilia A and Haemophilia B.
• Haemophilia A, also called Classic Haemophilia, is caused by a lack of or decrease in clotting factor VIII.
• Haemophilia B, also called Christmas Disease, is caused by a lack of or decrease in clotting factor IX.
• Haemophilia A is more severe than Haemophilia B.
• A person with Haemophilia A cannot synthesise a normal blood protein called antihaemophilic globulin (AHG) required for normal blood clotting. Therefore, even a very small cut may lead to continuous bleeding for a long time.
• In a person with Haemophilia B or Christmas Disease, blood protein plasma thromboplastin is absent.

What Are The Signs And Symptoms Of Haemophilia?

• The common signs and symptoms of haemophilia include bleeding of the mouth and gums, bleeding after circumcision, bleeding in the urine or stool, and bleeding after having shots, among others.

Why Is Haemophilia Also Known As ‘Royal Disease’?

• Haemophilia is also known as ‘royal disease’ because it affected the royal families of England, Germany, Russia, and Spain in the 19th and 20th centuries.
• The family pedigree of Queen Victoria, who ruled England from 1837 to 1901, shows a number of haemophilic descendants as she was believed to have been the carrier of Haemophilia B.
• The disease was carried through various royal family members for three generations after Queen Victoria, and subsequently disappeared.

Haemophilia in India:

• It is a rare disorder worldwide — one type, called Haemophilia A, occurs in about 1 in 5,000 births, while Haemophilia B is even rarer at about 1 in about 20,000 births.
• A vast number of cases, however, are believed to go unreported, particularly in India.
• According to the World Federation of Haemophilia’s Annual Global Survey 2017, released in October 2018, there were over 1.96 lakh persons living with haemophilia across the world in 2017.
• In the country-wise data, India emerges with the highest count at nearly 19,000.