Hunter Syndrome: MPS II | 09 Feb 2021
Why in News
Two brothers suffering from Mucopolysaccharidosis II or MPS II (Hunter Syndrome, Attenuated Type) have approached the Delhi High Court seeking direction to the Centre and AIIMS to provide them free treatment.
- MPS II is a rare disease that is passed on in families.
Key Points
- About: MPS II mostly affects boys and their bodies cannot break down a kind of sugar that builds bones, skin, tendons and other tissues.
- Cause: It is caused by changes (mutations) of the IDS gene that regulates the production of the iduronate 2-sulfatase (I2S) enzyme.
- This enzyme is needed to break-down complex sugars, known as glycosaminoglycans (GAGs), produced in the body.
- Impact: Lack of I2S enzyme activity leads to the accumulation of GAGs within cells, specifically inside the lysosomes.
- Lysosomes are compartments in the cell that digest and recycle different types of molecules.
- Conditions that cause molecules to build up inside the lysosomes, including MPS II, are called lysosomal storage disorders.
- The accumulation of GAGs increases the size of the lysosomes, which is why many tissues and organs are enlarged in this disorder.
- Symptoms: It is characterized by distinctive facial features, a large head, enlargement of the liver and spleen (hepatosplenomegaly), hearing loss, etc.
- Inheritance:
- MPS II is inherited in an X-linked recessive pattern, which means that this condition occurs almost exclusively in males. Females are generally unaffected carriers of this condition.
- In a family with more than one affected individual, the mother of the affected males must be a carrier. When a carrier female has a child, there is a 25% (1 in 4) chance that she will have an affected son.
Rare Diseases
- A rare disease is a health condition of low prevalence that affects a small number of people compared with other prevalent diseases in the general population.
- Though rare diseases are of low prevalence and individually rare, collectively they affect a considerable proportion of the population.
- 80% of rare diseases are genetic in origin and hence disproportionately impact children.
- Recently, the Delhi High Court has directed the Centre to finalise the National Health Policy for Rare Diseases of 2020 by March 2021 and make operational provision of crowdfunding envisaged under the law for treatment of high-cost rare diseases.