Fig. 1

The image presents the pedigree of 2 families with congenital heart defects (CHDs), sequencing chromatograms, and the conservation analysis of the mutated amino acids in the FLT4 and PTPN11 genes. A The image depicts Family I. A1 The image demonstrates the pedigree of Family I with individuals suffering from CHDs. The black arrow indicates the proband, and the affected and unaffected individuals are presented with filled and clean symbols, respectively. A2 The Sanger-based sequencing results in Family I show a heterozygous variant in the FLT4 gene in the proband (III-3) and her affected brother (III-2). The c.C244T variant in the FLT4 gene was detected in her healthy mother (II-6), while her father (II-5) did not carry this variant. The candidate variant was validated by Sanger-based sequencing using the reverse primer. A3 In Family I, the conservation of the p.R82X variant is shown. The variant site is highly conserved in various species. B The image depicts Family II. B1 The image demonstrates the pedigree of Family II with individuals suffering from CHDs. The black arrow indicates the proband, and the affected and unaffected individuals are represented by filled and clean symbols, respectively. B2 The Sanger-based sequencing results in Family II show a heterozygous variant in the PTPN11 gene in the proband (III-2) and her affected sister (III-1). The c.C1403T variant in the PTPN11 gene was detected in her healthy father (II-4), while her mother (II-5) did not carry this variant. The candidate variant was validated by Sanger-based sequencing using the forward primer. B3 In Family II, the conservation of the p.T468M variant is shown. The variant site is highly conserved in various species