Truncating and zinc‐finger variants in GLI2 are associated with hypopituitarism. Issue 4 (17th December 2021)

• Record Type: Journal Article
• Authors: Corder, Megan L.; Berland, Siren; Førsvoll, Jostein A.; Banerjee, Indraneel; Murray, Phil; Bratland, Eirik; Gokhale, David; Houge, Gunnar; Douzgou, Sofia
• Is Part Of: American journal of medical genetics. Volume 188:Issue 4(2022)
• Page Start: 1065
• Page End: 1074
• Publication Date: 2021-12-17
• Subjects: combined pituitary hormone deficiency -- Culler–Jones syndrome -- GLI2 -- holoprosencephaly -- solitary median maxillary central incisor; Medical genetics -- Periodicals; 616.14205
• DOI: 10.1002/ajmg.a.62611
• Languages: English
• ISSNs: 1552-4825

Abstract

Abstract: Variants in transcription factor GLI2 have been associated with hypopituitarism and structural brain abnormalities, occasionally including holoprosencephaly (HPE). Substantial phenotypic variability and nonpenetrance have been described, posing difficulties in the counseling of affected families. We present three individuals with novel likely pathogenic GLI2 variants, two with truncating and one with a de novo missense variant p.(Ser548Leu), and review the literature for comprehensive phenotypic descriptions of individuals with confirmed pathogenic (a) intragenic GLI2 variants and (b) chromosome 2q14.2 deletions encompassing only GLI2 . We show that most of the 31 missense variants previously reported as pathogenic are likely benign or, at most, low‐risk variants. Four Zn‐finger variants: p.(Arg479Gly), p.(Arg516Pro), p.(Gly518Lys), and p.(Tyr575His) were classified as likely pathogenic, and three other variants as possibly pathogenic: p.(Pro253Ser), p.(Ala593Val), and p.(Pro1243Leu). We analyze the phenotypic descriptions of 60 individuals with pathogenic GLI2 variants and evidence a morbidity spectrum that includes hypopituitarism (58%), HPE (6%) or other brain structure abnormalities (15%), orofacial clefting (17%) and dysmorphic facial features (35%). We establish that truncating and Zn‐finger variants in GLI2 are associated with a high risk of hypopituitarism, and that a solitary median maxillary central incisor is part of the GLI2 ‐related phenotypic variability. The most prevalent phenotypic feature is post‐axial polydactyly (65%) which is also the mildest phenotypic expression of the condition, reported in many parents of individuals with systemic findings. Our approach clarifies clinical risks and the important messages to discuss in counseling for a pathogenic GLI2 variant.