Fig. 3: Parental origin of the pathogenic c.776 G > T and the candidate c.1686−9 T > C KCNQ1 variants identified in the index patient.

DNA sequencing chromatograms of the KCNQ1 gene exon 5 (left) and intron 13 (right) from the index patient (a), father (b), and mother (c). The index patient’s variant c.776 G > T in exon 5 was detected in his mother, whereas the c.1686−9 T > C variant in intron 13 was detected in his father.