Fig. 2

a Histological findings of the tumor specimen. Two representative high-magnification views of hematoxylin and eosin-stained specimens are shown. Scale bars = 50 μm. b Schematic structure of RAD51D. Consensus regions/domains such as linker region and ATPase domain are shown in black or oblique-lined boxes. The number of amino acids (aa 1–328) is displayed on the top of the box. Amino acid numbers for each region/domain were obtained from a previous study by Chen et al. [13]. The number of exons (exons 1–10) translated to proteins are described below the box. The locus of RAD51D c.904-2A > T is in the carboxyl terminal of intron 9. Nucleotide numbering was based on the National Cancer for Biotechnology Information (NCBI) (http://www.ncbi.nlm.nih.gov) reference sequence NM_002878. c DNA sequences of wild-type (WT) RAD51D and the splice variant of RAD51D c.904-2A > T (Mut) with a plausible splicing acceptor site in the original exon 10 of RAD51D. AGs in gray boxes are splice acceptor sites of WT and an alternative splice site of Mut, respectively. TGA or TAG, outlined in black boxes, are termination codons. We suspect that a new splicing junction appeared 7 bp downstream from the 5′-end of exon 10, which resulted in the production of an aberrant mRNA. d Protein structure of WT (328 aa) and a representative variant of Mut (306 aa). The 7-base deletion of exon 10 (c.904_910del) causes a translational frameshift and produces a premature stop codon at six amino acids downstream from the 302nd of valine (abbreviated as V), as shown with an arrow. (p.P302Vfs*6). aa, amino acids; Ter, termination codon (stop codon)