Pedigree (A) and Sanger sequencing (B). A: Family’s pedigree. DNA samples were available from individuals marked with arrows. B: The segregation of the variant was confirmed in the twelve family members. The figure shows the forward and reverse strand chromatogram of the proband (IV: 5) and her father (III: 5) in the forward (F) and reverse (R) orientation. In the III: 5 s sequences the frameshift is evident in both orientations. The letters underneath are showing the reference sequence. In IV: 5 s sequences no frameshift is observed as expected since the variation is in homozygosity.