I was surprised to see that the second child wasn't sequenced earlier. A family of four study or even a study that includes grandparents is significantly more powerful then a trio study.
Even if only one individual displays the phenotypes it allows more variants to be eliminated and potentially allows an increased ability to distinguish sequencing errors from rare variants and new mutations. It also lets you more precisely identify recombination sites:
I was surprised to see that the second child wasn't sequenced earlier. A family of four study or even a study that includes grandparents is significantly more powerful then a trio study.
Even if only one individual displays the phenotypes it allows more variants to be eliminated and potentially allows an increased ability to distinguish sequencing errors from rare variants and new mutations. It also lets you more precisely identify recombination sites:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3037280/figure/F...