Using patient-derived cells, Sanger sequencing of cDNA confirmed that USH2A c.5777-1G > A causes the skipping of exon 29 leading to an in-frame deletion (p. Glu1926_Ala1952del) in an affected individual (PID III-2) compared with a control sample (Fig. 2d; Fig. 3a). Here, USH2A is linked to pelvic inflammatory disease.