Fig. 1.

The human seipin gene, major transcripts, and mutations. A: Three coding transcripts, modified from NCBI Gene webpage for BSCL2. Exons are shown as rectangles, introns as lines with direction of transcription indicated. Open reading frames in dark green, untranslated regions in light green. Exon numbers are indicated. B: Seipin protein isoforms and mutations. Yellow boxes are the two consensus TMDs. Amino acids are numbered separately, corresponding to isoforms 1 and 2. Black lines, normal sequence; red line, aberrant sequence of isoform 3 due to out-of-register exon splicing. Dots and tents underneath indicate mutations. Red dots are truncation mutations, green dots are missense mutations, and red tents correspond to large deletions. Arrowheads indicate the two mutations in the glycosylation site. Mutation lettering corresponds to those listed in Table 1.