I will be taking the first ever case-based NPLEX exam for ND's. What this means is that instead of having five sections (pathology, biochemistry, anatomy, physiology, microbiology) it will have many cases each with 5 questions relating to the case. This makes it more interesting to me. I am studying biochemistry by looking up metabolic dysfunctions and understanding their chemical pathogenesis.
For example, Hurler and Hunter syndrome are two different types of mucopolysaccharidosis. There are 9 times in all. Hurler is type I, Hunter is type II. Both lack (for different reasons) lysozymal enzymes that allow a person to breakdown glycosaminoglycans (GAGs), which are a big part of our connective tissue. So this CT builds up and causes trouble in all systems. Usually people with these disorders get diagnosed in the 2-4 years age range, because of developmental delays or poor hearing, and an odd look to their faces. They may be mentally retarded, have obstructive respiratory disease, or die of heart failure. It's bad, and it's all because they're missing an enzyme. Hunter syndrome victims don't have iduronate-2-sulfonase (I2S). Hunter syndrome is X-linked so most victims are male. Hurler syndrome victims don't have α-L-iduronidase. Excess mucopolysaccharides are excreted in the urine, and enzyme assays can provide definitive diagnosis. Prenatal diagnosis is done using amniocentesis and chorionic villus sampling.