Lifting the lid on unborn lethal Mendelian phenotypes through exome sequencing

PURPOSE: Mendelian phenotypes in humans vary from benign variants to lethal disorders. Embryonic lethal phenotypes that are similar to what has been known for a long time in mice have remained largely unknown because of the difficulty in arriving at a molecular diagnosis. The purpose of this study is to test whether next generation sequencing can reveal the underlying etiology of recurrent fetal loss. METHODS: We hypothesized that exome sequencing combined with autozygome analysis can reveal the underlying mutation in a family in which recurrent fetal loss was likely to be autosomal recessive in origin. RESULTS: A novel mutation in CHRNA1 was identified. This gene is known to cause multiple pterygium and fetal akinesia syndrome. CONCLUSION: This is the first report of exome sequencing to identify the cause of recurrent fetal loss and reveal the diagnosis of a lethal human phenotype. Our results should inspire a systematic examination of the extent of “unborn” Mendelian phenotypes in humans using next-generation sequencing.