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Comprehensive clinical features, including visual acuity, fundus appearance, and OCT findings were analyzed. Genetic testing was performed using targeted next-generation sequencing panels or whole-exome sequencing. The identified variants were classified according to ACMG guidelines to determine their pathogenicity.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Fourteen patients (11 males, 3 females; mean age, 41.4\u2009\u00b1\u200922.6 years) were included. Thirteen exhibited bilateral involvement. Clinical diagnoses comprised adult-onset vitelliform macular dystrophy (\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u20097), retinitis pigmentosa (\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u20096), and atypical macular dystrophy characterized by subtle, multifocal photoreceptor alterations (\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u20091). Splicing variants at the exon 7\u20138 junction (c.828+1G&gt;A, c.829-2_829-1delAG) and a splice acceptor variant at exon 9 (c.909\u20132A&gt;T) were identified in 12 of 14 patients (85.7%), with c.828+1G&gt;A being the most frequent (8\/14, 57.1%). 84.2% of the identified variants and 92.9% of the patients harbored loss-of-function mutations, including splicing, frameshift, and nonsense variants.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>\n                      Loss-of-function of\n                      <jats:italic>IMPG2<\/jats:italic>\n                      , including haploinsufficiency, appears to play a major role in\n                      <jats:italic>IMPG2<\/jats:italic>\n                      -associated retinopathy. The predominance and clustering of splice-site variants around the exon 7\u20138 junction may reflect a founder effect and regional sequence susceptibility.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s00417-026-07571-z","type":"journal-article","created":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T03:15:53Z","timestamp":1792725353000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Predominance and clustering of splice-site variants in Koreans with IMPG2-associated retinopathy: implications for haploinsufficiency and loss of function as disease mechanisms"],"prefix":"10.1007","author":[{"given":"Seok Hyeon","family":"Song","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sohee","family":"Jeon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hyewon","family":"Chung","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hyungwoo","family":"Lee","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yoon Jeon","family":"Kim","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hyeonju","family":"Ahn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Se Joon","family":"Woo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4266-1491","authenticated-orcid":false,"given":"Kwangsic","family":"Joo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,10,23]]},"reference":[{"issue":"2","key":"7571_CR1","doi-asserted-by":"publisher","first-page":"199","DOI":"10.1016\/j.ajhg.2010.07.004","volume":"13","author":"D Bandah-Rozenfeld","year":"2010","unstructured":"Bandah-Rozenfeld D, Collin RW, Banin E et al (2010) Mutations in IMPG2, encoding interphotoreceptor matrix proteoglycan 2, cause autosomal-recessive retinitis pigmentosa. 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