A: Squares indicate male family members, circles female family members. Black symbols represent clinically affected, gray represent unknown phenotype, clear symbols represent unaffected individuals. The arrow with 'P' indicates the proband in each family and 'us' indicates un-sequenced due to lack of DNA from that individual. The mutation in each family is given next to the family number; a horizontal black line above an individual's symbol indicates they are heterozygous for that mutation as identified by either whole exome sequencing (family 3 and 4) or Fluidigm array (family 1, 2, 5 and 6), and verified by Sanger sequencing. 