Why is it in the News?

A two-month-old girl, diagnosed with the rare disease ‘bubble baby syndrome,' becomes the youngest to receive a bone marrow transplant from an unrelated donor at Bai Jerbai Wadia Hospital for Children in Parel.

What is Bubble Baby Syndrome?

• 'Bubble baby syndrome,' medically known as Severe combined immunodeficiency (SCID) is a group of rare, life-threatening diseases that cause a child to be born with very little or no immune system.
• As a result, the child’s body is unable to fight off infections and can become very sick from infections like chickenpox, pneumonia and meningitis and can die within the first year of life.
• This condition falls under the category of primary immune deficiencies.
• The term "Bubble Baby Syndrome" is derived from the necessity for affected individuals to live in a highly controlled environment, as exposure to ordinary surroundings can pose fatal risks to children with SCID.
• What happens in Severe combined immunodeficiency (SCID)?
• In the developing fetus, the immune system originates in the bone marrow, where versatile stem cells can differentiate into three crucial types of blood cells: red blood cells, white blood cells (WBCs), and platelets.
  • Among these, white blood cells, particularly lymphocytes, play a vital role in safeguarding the body against infections.
• Lymphocytes consist of two main types: B-cells and T-cells.
  • T-cells identify, attack, and eliminate invaders, while B-cells produce antibodies that "remember" infections for future defence.
  • SCID is classified as a "combined" immunodeficiency as it impacts both of these infection-fighting white blood cell types.
• In SCID, the child's immune system exhibits either an insufficient quantity of lymphocytes or dysfunctional lymphocytes.
  • Consequently, the compromised immune system struggles to combat various germs such as viruses, bacteria, and fungi, leading to recurrent and severe infections.
• Causes: SCID results from inherited mutations in multiple genes, with one or both birth parents passing down the condition to their child.
• Symptoms: Although infants with SCID may initially appear healthy, signs of the disorder may manifest shortly after birth. These symptoms include
  • Failure to thrive
  • Chronic diarrhoea
  • Frequent, often severe respiratory infections
  • Oral thrush (a type of yeast infection in the mouth)
  • Other challenging-to-treat bacterial, viral, or fungal infections
• Treatment: SCID is considered a pediatric emergency, and without prompt intervention, affected babies are unlikely to survive beyond their first birthday.
• The primary treatment method involves a stem cell transplant, also known as a bone marrow transplant.
• In this procedure, the child receives stem cells from a donor with the hope that these new cells will reconstruct the compromised immune system, offering a chance for a healthier and more sustainable life.

Bone marrow transplant

• The most common treatment for SCID is an allogeneic bone marrow transplant, which will introduce normal infection-fighting cells into your child’s body.
  • Allogeneic transplants use stem cells from a relative or an unrelated donor from the National Marrow Donor Program.
• An allogeneic bone marrow transplant involves taking cells from the bone marrow (the soft, spongy tissue found in bones) of a healthy donor and giving them to a child after the child’s diseased bone marrow has been eliminated.
• Doctors at Children’s Hospital will screen your child’s family for potential bone marrow matches.
  • While a tissue-matched sibling offers the greatest chance of curing SCID, they are not often available.
  • Instead, most patients receive bone marrow donations from their parents or unrelated matched donors.