Fig. 1

RET sequence variants detected in 16 HSCR patients with molecular details on three mosaic variants. a Schematic representation of the exon-intron structure of RET. Black bars represent exons, and black lines represent introns, with patient mutations indicated above the RET genomic structure. b Domain structure of RET (GenBank: NP_066124), including the positions (numbers) of identified amino acid alterations. Abbreviations: SP, signal peptide; CYS, cysteine-rich domain; TM, transmembrane domain; TK, tyrosine kinase domain. Inherited, de novo and mosaic variants are shown in black, green and red, respectively, in (a) and (b). c Dideoxy-sequence traces for the three families with RET mosaic mutations. In family 1, electropherograms from the patients’ father and mother do not show presence of the variant. In family 5, a small proportion of the mutant c.845dupT allele is present in the proband’s mother, based on both the presence of a small T peak and the reduced relative height of the normal G peak. In family 10, a small proportion of the mutant c.2308C > T allele is present in the proband’s father, based on both the presence of a small T peak and a normal sized C peak. d Digital droplet PCR results on families 1, 5 and 10. All positive droplets (those above the threshold intensity indicated by the pink line) are indicated by a red arrow