LHX2 haploinsufficiency causes a variable neurodevelopmental disorder

• Published in: Genetics in medicine Vol. 25; no. 7; p. 100839
• Main Authors: Schmid, Cosima M., Gregor, Anne, Costain, Gregory, Morel, Chantal F., Massingham, Lauren, Schwab, Jennifer, Quélin, Chloé, Faoucher, Marie, Kaplan, Julie, Procopio, Rebecca, Saunders, Carol J., Cohen, Ana S.A., Lemire, Gabrielle, Sacharow, Stephanie, O’Donnell-Luria, Anne, Segal, Ranit Jaron, Kianmahd Shamshoni, Jessica, Schweitzer, Daniela, Ebrahimi-Fakhari, Darius, Monaghan, Kristin, Palculict, Timothy Blake, Napier, Melanie P., Tao, Alice, Isidor, Bertrand, Moradkhani, Kamran, Reis, André, Sticht, Heinrich, Chung, Wendy K., Zweier, Christiane
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2023; Nature Publishing Group
• Subjects: ASD; Autism Spectrum Disorder; Autism Spectrum Disorder - genetics; Genetics; Haploinsufficiency; Haploinsufficiency - genetics; Humans; Intellectual Disability; Intellectual Disability - complications; Intellectual Disability - genetics; LHX2; Life Sciences; LIM-Homeodomain Proteins; LIM-Homeodomain Proteins - genetics; Microcephaly; NDD; Neurodevelopmental disorder; Neurodevelopmental Disorders; Neurodevelopmental Disorders - pathology; Transcription Factors; Transcription Factors - genetics; ASD; Intellectual disability; Neurodevelopmental disorder; Microcephaly; LHX2; NDD
• ISSN: 1098-3600; 1530-0366; 1530-0366
• DOI: 10.1016/j.gim.2023.100839

LHX2 encodes the LIM homeobox 2 transcription factor (LHX2), which is highly expressed in brain and well conserved across species, but it has not been clearly linked to neurodevelopmental disorders (NDDs) to date. Through international collaboration, we identified 19 individuals from 18 families with variable neurodevelopmental phenotypes, carrying a small chromosomal deletion, likely gene-disrupting or missense variants in LHX2. Functional consequences of missense variants were investigated in cellular systems. Affected individuals presented with developmental and/or behavioral abnormalities, autism spectrum disorder, variable intellectual disability, and microcephaly. We observed nucleolar accumulation for 2 missense variants located within the DNA-binding HOX domain, impaired interaction with co-factor LDB1 for another variant located in the protein-protein interaction–mediating LIM domain, and impaired transcriptional activation by luciferase assay for 4 missense variants. We implicate LHX2 haploinsufficiency by deletion and likely gene-disrupting variants as causative for a variable NDD. Our findings suggest a loss-of-function mechanism also for likely pathogenic LHX2 missense variants. Together, our observations underscore the importance of LHX2 in the nervous system and for variable neurodevelopmental phenotypes.