The additional diagnoses in this cohort highlight some key advantages of massively parallel sequencing, namely, identification of unexpected diagnoses or a typical phenotypes, for example, the patient diagnosed with a congenital myasthenic syndrome; and variants in large genes such as TTN, NEB, and RYR1, which have been technically difficult and prohibitively expensive to Sanger sequence. The gene discussed is TTN; the disease is Congenital myasthenic syndromes.