RORA neurodevelopmental disorder

Inspired by a patient

Talarico M, de Bellescize J, De Wachter M, Le Guillou X, Le Meur G, Egloff M, Isidor B, Cogné B, Beysen D, Rollier P, Fradin M, Pasquier L, Guella I, Hickey SE, Benke PJ, Shillington A, Kumps C, Vanakker O, Gerkes EH, Lakhani S, Romanova I, Kanivets I, Brugger M, Vill K, Caylor RC, Skinner C, Tinker RJ, Stödberg T, Nümann A, Haack TB, Deininger N, Hengel H, Jury J, Conrad S, Mercier S, Yoon G, Tsuboyama M, Barcia G, Gitiaux C, Rio M, Bevot A, Redon S, Uguen K, Wonneberger A, Schulz A, Timmann D, Karlowicz DH, Chatron N, Carnevale A, Mahida S, Õunap K, Kury S, Cabet S, Lesca G. RORA-neurodevelopmental disorder: A unique triad of developmental disabilities, cerebellar anomalies, and myoclonic seizures. Genet Med. 2025 Apr;27(4):101347. doi: 10.1016/j.gim.2024.101347. Epub 2024 Dec 17. PMID: 39707840.

Abstract

Purpose: RORA encodes the RAR-related orphan receptor-α, playing a pivotal role in cerebellar maturation and function. Here, we report the largest series of individuals with RORA-related-neurodevelopmental disorder.

Methods: Forty individuals (30 unrelated; 10 siblings from 4 families) carrying RORA pathogenic/likely pathogenic variants were collected through an international collaboration.

Results: The 33 variants (29 de novo, 4 inherited, and 1 shared), identified by genome/exome sequencing (n = 21), chromosomal microarray analysis (n = 7), or gene panels (n = 4), included frameshift (n = 18/33), missense (n = 9/33), and stop codon (n = 6/33). Developmental disability (n = 32/37), intellectual disability (n = 22/32), and cerebellar signs (n = 25/34) were the most striking clinical features. Cerebellar symptoms were divided into early-onset, late-onset, and progressive subgroups. Cerebellar hypoplasia, atrophy, or both (n = 16/25) were more frequent in individuals with missense variants in the DNA-binding domain. Epilepsy (n = 18/38), with prominent myoclonic seizure types (n = 11/18), was classified in (1) genetic generalized epilepsy (n = 10/18) with a syndromic diagnosis identifiable for 6: epilepsy with eyelid myoclonia (n = 5/6) and epilepsy with myoclonic absence (n = 1/6); (2) developmental and epileptic encephalopathy (n = 5/18); and (3) unclassified (n = 3/18). A participant with rapid deterioration of visual acuity and cone/rod dystrophy was reported.

Conclusion: Missense variants in DNA-binding domain correlate to a more severe cerebellar phenotype. The RORA-related-neurodevelopmental disorder triad comprises developmental disability, cerebellar features, and a spectrum of myoclonic epilepsy.

Guissart C, Latypova X, Rollier P, Khan TN, Stamberger H, McWalter K, Cho MT, Kjaergaard S, Weckhuysen S, Lesca G, Besnard T, Õunap K, Schema L, Chiocchetti AG, McDonald M, de Bellescize J, Vincent M, Van Esch H, Sattler S, Forghani I, Thiffault I, Freitag CM, Barbouth DS, Cadieux-Dion M, Willaert R, Guillen Sacoto MJ, Safina NP, Dubourg C, Grote L, Carré W, Saunders C, Pajusalu S, Farrow E, Boland A, Karlowicz DH, Deleuze JF, Wojcik MH, Pressman R, Isidor B, Vogels A, Van Paesschen W, Al-Gazali L, Al Shamsi AM, Claustres M, Pujol A, Sanders SJ, Rivier F, Leboucq N, Cogné B, Sasorith S, Sanlaville D, Retterer K, Odent S, Katsanis N, Bézieau S, Koenig M, Davis EE, Pasquier L, Küry S. Dual Molecular Effects of Dominant RORA Mutations Cause Two Variants of Syndromic Intellectual Disability with Either Autism or Cerebellar Ataxia. Am J Hum Genet. 2018 May 3;102(5):744-759. doi: 10.1016/j.ajhg.2018.02.021. Epub 2018 Apr 12. PMID: 29656859; PMCID: PMC5986661.

Abstract

RORα, the RAR-related orphan nuclear receptor alpha, is essential for cerebellar development. The spontaneous mutant mouse staggerer, with an ataxic gait caused by neurodegeneration of cerebellar Purkinje cells, was discovered two decades ago to result from homozygous intragenic Rora deletions. However, RORA mutations were hitherto undocumented in humans. Through a multi-centric collaboration, we identified three copy-number variant deletions (two de novo and one dominantly inherited in three generations), one de novo disrupting duplication, and nine de novo point mutations (three truncating, one canonical splice site, and five missense mutations) involving RORA in 16 individuals from 13 families with variable neurodevelopmental delay and intellectual disability (ID)-associated autistic features, cerebellar ataxia, and epilepsy. Consistent with the human and mouse data, disruption of the D. rerio ortholog, roraa, causes significant reduction in the size of the developing cerebellum. Systematic in vivo complementation studies showed that, whereas wild-type human RORA mRNA could complement the cerebellar pathology, missense variants had two distinct pathogenic mechanisms of either haploinsufficiency or a dominant toxic effect according to their localization in the ligand-binding or DNA-binding domains, respectively. This dichotomous direction of effect is likely relevant to the phenotype in humans: individuals with loss-of-function variants leading to haploinsufficiency show ID with autistic features, while individuals with de novo dominant toxic variants present with ID, ataxia, and cerebellar atrophy. Our combined genetic and functional data highlight the complex mutational landscape at the human RORA locus and suggest that dual mutational effects likely determine phenotypic outcome.

Sayad A, Noroozi R, Omrani MD, Taheri M, Ghafouri-Fard S. Retinoic acid-related orphan receptor alpha (RORA) variants are associated with autism spectrum disorder. Metab Brain Dis. 2017 Oct;32(5):1595-1601. doi: 10.1007/s11011-017-0049-6. Epub 2017 Jun 12. PMID: 28608249.

Abstract

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with various epidemiologic, genetic, epigenetic, and environmental factors being associated with it. The observed sex bias in ASD towards male has prompted investigators to propose sex-dependent mechanisms for ASD. Retinoic acid-related orphan receptor-alpha (RORA) is a new autism candidate gene that has been shown to be differentially regulated by male and female hormones. Previous studies have shown deregulation of its expression in the prefrontal cortex and the cerebellum of ASD patients. In the present study we aimed at identification of the possible associations between two functional polymorphisms in the RORA gene (rs11639084 and rs4774388) and the risk of ASD in 518 Iranian ASD patients and 472 age, gender, and ethnic-matched healthy controls by means of tetra primer-amplification refractory mutation system-PCR. The allele and genotype frequencies of rs11639084 were not significantly different between patients and controls. However, the allele frequencies of rs4774388 showed significant overrepresentation of T allele in patients compared with controls (P = 0.04, OR (95% CI) =1.21 (1.01-1.46)). The rs4774388-TT genotype was significantly higher in patients compared with controls and was associated with ASD risk in dominant inheritance model (P = 0.04, OR (95% CI) =0.77 (0.59-0.99)). Haplotype analysis showed significant association of two estimated blocks of rs11639084/ rs4774388 with ASD risk. Consequently, the present data provide further evidence for RORA participation in the pathogenesis of ASD.