Variant filtering
Ten genes (MYOC, CYP1B1, LTBP2, PITX2, FOXC1, PAX6, TEK, ANGPT1,
LMX1B, CPAMD8 ) known to cause various forms of early-onset glaucoma
were initially screened for pathogenic mutations. If no plausible
causative variants were identified, the exome data was examined for
novel pathogenic variants. Disease-causing mutations are expected to be
rare, disrupt protein function, and have high estimates of
pathogenicity. Variants were filtered using 1) minor allele frequency
(MAF) from the Exome Aggregation Consortium (ExAC) database (MAF less
than 0.001 were retained), 2) tools to score variants according to
phylogenetic conservation (GERP) and its effect on protein structure
(SIFT, PolyPhen, conserved predicted pathogenic variants were obtained),
3) ocular expression, and any known functional or human disease
involvement (ocular expression was prioritized) and 4) examining
segregation in all available family members. The family A and B pedigree
structures suggested dominant inheritance; hence, heterozygous variants
were prioritized. Sanger sequencing was used to investigate segregation
of candidate variants in all available family members.