• Immunology (including allergy)
• other endocrinology
• drugs: endocrine system
• molecular genetics
• metabolic disorders

The power of massively parallel sequencing (MPS) combined with target enrichment technologies has led, in the space of barely 2 years, to a true revolution in our ability to explore the genome for sequence changes responsible for phenotypes of interest. While the resequencing efforts in search of low-frequency variants involved in complex traits have only generated hopes to date, targeted sequencing can claim one resounding success: the rate at which reports are appearing that identify the gene mutated in rare monogenic diseases is astounding and growing by the month. The sequencing of coding exons and adjacent splicing elements, sites of the vast majority of mutations responsible for Mendelian diseases, is now a routine and relatively inexpensive procedure, blurring the distinction between discovery and service to the individual.

Of the several examples of exome sequencing results highlighted in this issue, the report by Majewski et al1 is a case in point. An adult female with a solid clinical diagnosis of Leber's congenital amaurosis (LCA) …