WRN mutation update. The 35 exons of WRN gene locus and WRN protein are shown. Exon 1 and part of 35 are non-coding. The relationship between exons and functional domains is indicated by extending a shaded region from the gene region to the protein functional domains. Known functional domains are indicated by the shaded regions extending from the gene to the protein functional domains. Those domains are the exonuclease and helicase domains, RecQ helicase conserved region (RQC), helicase RNaseD C-terminal conserved region (HRDC), and the nuclear localization signal (NLS). Mutations are grouped by the types shown on the left. Large genomic rearrangements are shown on top using horizontal brackets, labeled “Dup” for duplication or “Del” for deletion. Mutations that affect splicing are indicated with inverted triangles above the WRN locus. Small genomic changes, such as insertions and deletions (Indels), are indicated below the gene locus, using a black-filled diamond shape (◆), whereas stop codons are indicated with a closed triangle (▲). Missense mutations are indicated with black-filled circles (●). Newly identified mutations are indicated for all mutation types by an asterisk (*).