Relevant molecular techniques for diagnosis of endocrine disorders in adolescents and children

Through the use of molecular techniques many genetic and infectious disorders affecting children can be diagnosed. All of these techniques are currently being used clinically, so the practicing physician should have some background in the basic concepts and uses. Southern blots can detect large deletions, usually at least 50-100 base pairs (bp). Restriction-fragment length polymorphisms (RFLPs) may be detected by Southern blotting or polymerase chain reaction (PCR) analysis. PCR may detect deletions or insertions smaller than 50 bp, but DNA sequencing is usually required to determine the presence of point mutations. Although newer techniques such as denaturing gradient gels can detect single base mutations and pulsed-field gel electrophoresis can detect large mutations, they currently do not have widespread use clinically. New molecular genetic techniques will continue to evolve, which should someday allow automation of DNA diagnosis.