ABSTRACT
Until recently, the molecular identification of rare genes for monogenic disorders was laborious, often consuming many years of painstaking effort. Now, in the era of massively parallel DNA sequencing (next-generation sequencing), it is becoming routine. We cover the principles in Section 8.1. Some difficulties remain, however, because for some singlegene disorders the disease phenotypes do not have a very well-defined, distinctive pathology. And a good deal of follow-up work will be needed to dissect out all the factors in monogenic diseases, which are sometimes rather complex, as described in Section 7.7.
