Fig. 1

Genetic findings in the reported patient. (A) Pedigree of the family showing the affected patient carrying compound heterozygous variants in CNTNAP2: the paternally inherited missense c.2752C > T, p.(Leu918Phe) (ENST00000361727.3) in exon 17 and the maternally inherited c.97 +?_209-?dup duplication in intron 1 (for which the exact breakpoints have not been mapped). (B) Sanger sequencing traces showing the heterozygous single nucleotide variant in the proband and his father, consisting of leucine to phenylalanine substitution. (C) Confirmation of exon 2 duplication. RT-qPCR from genomic DNA shows that the patient and his mother have one extra copy of exon 2 as compared to the father. The duplication breakpoint is located after exon 2 since the first ~ 200 bp of intron 2 are still duplicated. Three technical replicates per condition. (D) Localization of inherited mutations on CNTNAP2. The maternally inherited duplication begins in the first intron and overlaps a binding site for the transcription factor FOXP2. Approximate boundaries of the duplication could be determined from the array-CGH and PCRs (see also supp material), indicating that the duplication also involves exon 2 and part of intron 2. The paternally inherited mutation is located in exon 17. (E) Predicted consequences of CNTNAP2 variants at the protein level. Exon 2 encodes the first part of the discoidin domain, the sequence of which is duplicated by the maternally inherited c.97 +?_209-?dup variant. The paternally inherited p.(Leu918Phe) variant results in a amino acid change in exon 17, which encodes the third laminin G domain of CASPR2. Both domains belong to the extracellular region of CASPR2 which facilitates protein-protein interactions. Supplementary data contain additional details on the methodology and results. Discoidin = Discoidin homology domain, Laminin G = Laminin G domain, EGF = EGF-like domain, FBG = Fibrinogen-like region, TM = transmembrane domain, 4.1B = Protein 4.1 binding domain, PDZ = PDZ interaction domain