Teachable moment in classrooms:
- cellular basis of life chapter – concept of one gene, one protein
- cellular basis of life chapter – concept of gene mutation leading to protein malfunction
- cellular basis of life – active transporter proteins use ATP to move substances against concentration gradient
- tissues chapter – collagen fibers in connective tissues
- nervous system chapter – function of the blood-brain barrier
The news item: Recently the following news item appeared online:
Zydus Lifesciences Sentynl Gets USFDA Approval for ZYCUBO for Menkes Disease First Approved Therapy in United States – CNBC TV18
The US drug regulator approval is backed by positive clinical data showing a nearly 80% reduction in the risk of death in patients who received early treatment with ZYCUBO®, compared with an untreated external control group.
The article states that the newly-approved drug, Zycubo, is for the treatment of X-linked Menkes disease that is characterized by impaired copper transport.
So, Why Do I Care?? Menkes disease affects about 3000 children yearly in the USA. Most children die by the age of three, and that is the best evidence that treatment attempts have not been successful in fighting this disease. The relatively simple drug, Zycubo, by simple injection has proven successful in reducing disease severity and increasing survival to past age 6. This gives hope for the patients and the parents, and opens the door to future treatments that may be even more effective.
Plain English, Please!!! First, let’s talk about why copper is important for our bodies. Copper is a cofactor for several enzymes. A cofactor is a small atom or molecule that change the active site of the enzyme to make the enzyme more efficient. Picture the enzyme as a hand drill. The hand drill cannot work without a drill bit, that twisting piece of steel that has to be inserted into the hand drill. In this case the drill bit is the cofactor. One such copper-dependent enzyme, superoxide dismutase, removes harmful oxidizing chemicals from the cells. When this enzyme is disabled by copper deficiency, the neurons lower their activities leading to the deterioration of the nervous system we see in Menkes disease. Another enzyme, lysine oxidase, cross-links, strengthens collagen fibers, and when this enzyme is disabled by copper deficiency, weak collagen fibers are created leading to the weakened aorta and bones in Menkes disease.
Second, let’s talk about the nature of the genetic mutation in Menkes disease. When we think about copper deficiency, first we think about the possible deficiency of absorption from the small intestine. Copper absorption from the small intestine