Table 1.

Number of Variants Identified in Exome Sequencing Data of Patient A-3 and Filtering on the Basis of Genotyping Data

	Total	Nonsynonymous Heterozygous Variants Not in 1000 Genomes	Nonsynonymous Homozygous Variants Not in 1000 Genomes	Nonsense/Splice Site/Frameshifting Indel Heterozygous Variants Not in 1000 Genomes	Nonsense/Splice Site/Frameshifting Indel Homozygous Variants Not in 1000 Genomes
Full exome	16,649	329	42	80	37
Within segments where both parental haplotypes are shared with affected sibling	2,914	69	12	26	10
Within regions of homozygosity	577	2	6	0	4
Within regions of homozygosity shared with affected sibling	161	2	2a	0	1

A threshold of 5 cM was used for segments where both parental haplotypes are shared in the two affected siblings. Regions of homozygosity were considered significant if larger than 3 cM. The 20100804 sequence and alignment release of the 1000 genomes project was used (628 individuals).

^aThese two variants (p.Glu180Val in ARMC9 [rs1626451] and p.Arg302His in GEN1) cannot be fully excluded, but on the basis of physiological relevance, the loss-of-function KCNJ13 change is much more likely disease causing.