Pediatric Whole Exome Sequencing: an Assessment of Parents' Perceived and Actual Understanding.

Whole exome sequencing (WES) is an integral tool in the diagnosis of genetic conditions in pediatric patients, but concerns have been expressed about the complexity of the information and the possibility for secondary findings that need to be conveyed to those deciding about WES. Currently, there is no validated tool to assess parental understanding of WES. We developed and implemented a survey to assess perceived and actual understanding of WES in parents who consented to clinical WES for their child between July 2013 and May 2015. Fifty-three eligible surveys were returned (57% response rate). Areas with both low perceived and actual understanding about WES included how genes are analyzed and lack of protection against life insurance discrimination. Parents also had low actual understanding for two questions related to secondary findings - reporting of secondary findings in a parent (if tested) and whether secondary findings can be related to traits such as height and hair color. Further work to develop a validated tool to assess understanding of WES would be beneficial as WES is integrated more frequently into clinical care.

Hemophagocytic lymphohistiocytosis in a female patient due to a heterozygous XIAP mutation and skewed X chromosome inactivation.

Genetic forms of hemophagocytic lymphohistiocytosis (HLH) are caused by mutations in autosomal recessive genes affecting perforin-dependent cytotoxic function and two X-linked genes affecting distinct cell signaling pathways: SH2D1A and XIAP. HLH caused by mutations in X-linked genes is typically found only in males. Here we report the occurrence of HLH in a female caused by a heterozygous mutation in XIAP. Flow cytometric studies confirmed the absence of XIAP protein expression, while an X chromosome inactivation assay revealed an extreme skewing ratio of 99:1. This finding demonstrates that females are susceptible to X-linked forms of HLH through skewed X chromosome inactivation.