Massively parallel sequencing technologies provide new opportunities to discover causal variants and -narrow down candidate genes responsible for human Mendelian disorders. Such information can in turn provide new insights into understanding the basic science behind, as well as improving diagnosis and treatment for, these disorders. In this chapter, we review experimental design and data analysis for sequencing studies of human immune disorders. We discuss optimal experimental designs for sample selection and sequencing approaches, as well as key aspects of data analysis such as filtering and prioritization of identified variants.