Syllabus

GS3: Awareness in the fields of IT, Space, Computers, Robotics, Nano-technology, Bio-technology, and issues relating to Intellectual Property Rights.

Context: A nine-month-old boy born with a rare genetic disorder called CPS1 deficiency has become the first known patient to receive a customised gene-editing treatment.

More on the News 

• The treatment, described in a May 15 report in the New England Journal of Medicine, was developed by Scientists from the University of Pennsylvania and the Children’s Hospital of Philadelphia. 
• They used “base editing,” an advanced form of CRISPR, to create a personalized treatment.

About CPS-1 deficiency

• Carbamoyl Phosphate Synthetase 1 Deficiency (CPSID) is a rare inherited disorder where the body lacks or has very low levels of an important enzyme called CPS1.
  CPS1 is one of five enzymes needed for the urea cycle, the process that removes extra nitrogen from the body.
  When CPS1 is missing or not working properly, nitrogen builds up in the blood as ammonia, a condition known as hyperammonemia.
  Ammonia is toxic, especially to the brain.
• In affected infants or children, Symptoms may include: Vomiting, Refusal to eat, Extreme sleepiness (lethargy) and Coma, in severe cases
• Cause and Inheritance: CPSID is caused by mutations in a gene that produces the CPS1 enzyme.
  It is inherited in an autosomal recessive pattern, meaning a child must inherit the faulty gene from both parents to be affected.
• CPS-1 deficiency has a 50% mortality rate in early infancy.

What is Base-Editing?

• Base editing is an advanced, more precise version of CRISPR-Cas9. 
• Unlike CRISPR-Cas9, base editing does not make a double-strand break. Rather, it enables targeted single-base conversions with the help of a Cas9 enzyme fused to a base-modifying enzyme. 
• This allows scientists to fix the mispairing of the bases by changing one specific base.
  For instance, mispaired A-C bases can be corrected to A-T by converting C to T.