Intellectual disability syndromic and non-syndromic
Gene: NR4A2 Green List (high evidence)Green List (high evidence)
Singh et al (2020 - https://doi.org/10.1038/s41436-020-0815-4) provide details on the phenotype of 9 unrelated individuals with NR4A2 pathogenic variants (in almost all cases de novo).
Features included hypotonia (in 6/9), DD (9/9), varying levels of ID (mild to severe in 8/8 for whom this information was available), seizures (6/9 - variable epilepsy phenotypes), behavioral problems (5/9 - with autism reported for one). Less frequent features incl. hypermobility (in 3), ataxia/movement disorder (in 3).
8 total pLoF and missense variants were identified as de novo events following trio exome sequencing with Sanger validation (7/8 variants). For 1(/8) individual with a stopgain variant, a single parental sample was available. A 9th individual was found to harbor a ~3.7 Mb 2q deletion spanning also other genes (which might also contribute to his phenotype of epilepsy).
Only the effect of a variant affecting the splice-acceptor site was studied (c.865-1_865delGCinsAAAAAGGAGT - NM_006186.3) with RT-PCR demonstrating an out-of-frame skipping of exon 4. Another variant (NM_006186.3:c.325dup) found in a subject with DD, ID and epilepsy had also previously been reported in another individual with similar phenotype of epilepsy and ID (Ramos et al - PMID: 31428396 - the variant was de novo with other causes for his phenotype excluded).
As discussed by Singh et al, NR4A2 encodes a steroid-thyroid-retinoid receptor which acts as a nuclear receptor transcription factor. The authors summarize previous reports on NR4A2 haploinsufficiency (NR4A2 has a pLI of 1 and HI score of 1.28% - Z-score is 2.24).
The authors comment on mouse models suggesting a role of NR4A2 for dopaminergic neurons, and provide plausible explanations for the phenotype of ID/seizures.
Previous reviews from PanelApp UK:
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In a study of 457 autism families (Feliciano et al. - doi.org/10.1101/516625) the authors provide phenotypic information on a further individual with ASD and ID. This subject (SP0041645 - SPARK cohort) harbored a de novo frameshift variant (p.G231fs using ENST00000409572.1 as reference). Table 2 includes also the individual previously reported by Iossifov et al. who also presented with ASD and ID (11172.p1 - SSC cohort - PMID and details discussed below).
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Recent publications provide several lines of evidence that pathogenic NR4A2 variants cause DD/ID and/or autism spectrum disorder (ASD).
Lévy et al. (PMID: 29770430) summarize the phenotype of 2q24.1 microdeletions spanning either only NR4A2 [2 new patients as well as an individual reported by Reuter et al (PMID: 28544326)] or both NR4A2 and GPD2 (1 patient from this study as well as 2 further from Leppa et al. (PMID: 27569545) and Barge-Schaapveld et al. (PMID: 23554088)]. All these CNVs had occurred as de novo events. Common features included - among others - language impairment (6/6), ID (6/6), ASD (3/4) or abnormal behaviour (4/4).
As the authors note, NR4A2 belongs to a subfamily of highly conserved transcription factors. The gene is involved in several developmental processes, among others in neuronal development. Previous studies have also shown high expression in human fetal brain as well as a role in the development of language-related brain regions.
The absence of CNVs in general population encompassing NR4A2 (and presence of such CNVs spanning GDP2) as well as the minimal deletions confined to NR4A2 suggest that happloinsufficiency of NR4A2 is responsible for the DD/ID/ASD phenotypes. This is also supported by the HI index of 1.28 as well as pLI of 0.99.
Guo et al. (PMID: 30504930) report on a patient with de novo frameshift variant (p.P201Rfs*82) and provide a summary of individuals with de novo missense variants (schematic overview in suppl. fig. S4) previously reported in larger DD/ID/ASD cohorts, namely :
- The DDD study (PMID: 28135719) : subjects DDD4K.00386 (R312Q - https://decipher.sanger.ac.uk/ddd/research-variant/1e7622c3a0ba1b506c5808ccea46e759#overview) and DDD4K.04161 (R289P - https://decipher.sanger.ac.uk/ddd/research-variant/673e8e570d28dd0c5797ddafb22e53eb#overview)
- By Lelieveld et al. (PMID: 27479843) : patient with ID and V307G
- By Iossifov et al. (PMID: 25363768) : subject with ASD and Y275H.
[All these appear to cluster in a region of missense constraint : https://decipher.sanger.ac.uk/gene/NR4A2#overview/protein-info].
NR4A2 is not associated with any phenotype in OMIM, nor in G2P.
The gene is included in gene panels for intellectual disability offered by diagnostic laboratories (incl. Radboudumc).
As a result, it could be considered for inclusion in this panel possibly as green (or amber).
Sources: Literature, Radboud University Medical Center, NijmegenCreated: 9 May 2020, 7:42 p.m. | Last Modified: 9 May 2020, 7:42 p.m.
Panel Version: 0.2631
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Phenotypes
Generalized hypotonia; Global developmental delay; Intellectual disability; Seizures; Behavioral abnormality; Abnormality of movement; Joint hypermobility
Publications
I don't know
Comment when marking as ready: Upgrade to Green in view of new publication reporting 9 additional individuals.Created: 9 May 2020, 10:30 p.m. | Last Modified: 9 May 2020, 10:30 p.m.
Panel Version: 0.2632
Disputed link of polymorphisms in this gene with susceptibility to Parkinson's disease. Single family reported with ID and de novo variant in this gene, no functional data (31428396). Another de novo truncating variant reported as part of a large autism study (30504930). Three individuals with CNVs only encompassing this gene and ID (29770430).Created: 8 Dec 2019, 4:01 a.m. | Last Modified: 8 Dec 2019, 4:01 a.m.
Panel Version: 0.881
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Intellectual disability; rolandic epilepsy; autism
Publications
Phenotypes for gene: NR4A2 were changed from Intellectual disability; rolandic epilepsy; autism to Intellectual developmental disorder with language impairment and early-onset DOPA-responsive dystonia-parkinsonism, MIM# 619911
Gene: nr4a2 has been classified as Green List (High Evidence).
Gene: nr4a2 has been classified as Green List (High Evidence).
Gene: nr4a2 has been classified as Amber List (Moderate Evidence).
Phenotypes for gene: NR4A2 were changed from to Intellectual disability; rolandic epilepsy; autism
Publications for gene: NR4A2 were set to
Mode of inheritance for gene: NR4A2 was changed from Unknown to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Gene: nr4a2 has been classified as Amber List (Moderate Evidence).
gene: NR4A2 was added gene: NR4A2 was added to Intellectual disability, syndromic and non-syndromic_GHQ. Sources: Expert Review Green,Genetic Health Queensland Mode of inheritance for gene: NR4A2 was set to Unknown
If promoting or demoting a gene, please provide comments to justify a decision to move it.
Genes included in a Genomics England gene panel for a rare disease category (green list) should fit the criteria A-E outlined below.
These guidelines were developed as a combination of the ClinGen DEFINITIVE evidence for a causal role of the gene in the disease(a), and the Developmental Disorder Genotype-Phenotype (DDG2P) CONFIRMED DD Gene evidence level(b) (please see the original references provided below for full details). These help provide a guideline for expert reviewers when assessing whether a gene should be on the green or the red list of a panel.
A. There are plausible disease-causing mutations(i) within, affecting or encompassing an interpretable functional region(ii) of this gene identified in multiple (>3) unrelated cases/families with the phenotype(iii).
OR
B. There are plausible disease-causing mutations(i) within, affecting or encompassing cis-regulatory elements convincingly affecting the expression of a single gene identified in multiple (>3) unrelated cases/families with the phenotype(iii).
OR
C. As definitions A or B but in 2 or 3 unrelated cases/families with the phenotype, with the addition of convincing bioinformatic or functional evidence of causation e.g. known inborn error of metabolism with mutation in orthologous gene which is known to have the relevant deficient enzymatic activity in other species; existence of an animal model which recapitulates the human phenotype.
AND
D. Evidence indicates that disease-causing mutations follow a Mendelian pattern of causation appropriate for reporting in a diagnostic setting(iv).
AND
E. No convincing evidence exists or has emerged that contradicts the role of the gene in the specified phenotype.
(i)Plausible disease-causing mutations: Recurrent de novo mutations convincingly affecting gene function. Rare, fully-penetrant mutations - relevant genotype never, or very rarely, seen in controls. (ii) Interpretable functional region: ORF in protein coding genes miRNA stem or loop. (iii) Phenotype: the rare disease category, as described in the eligibility statement. (iv) Intermediate penetrance genes should not be included.
It’s assumed that loss-of-function variants in this gene can cause the disease/phenotype unless an exception to this rule is known. We would like to collect information regarding exceptions. An example exception is the PCSK9 gene, where loss-of-function variants are not relevant for a hypercholesterolemia phenotype as they are associated with increased LDL-cholesterol uptake via LDLR (PMID: 25911073).
If a curated set of known-pathogenic variants is available for this gene-phenotype, please contact us at panelapp@genomicsengland.co.uk
We classify loss-of-function variants as those with the following Sequence Ontology (SO) terms:
Term descriptions can be found on the PanelApp homepage and Ensembl.
If you are submitting this evaluation on behalf of a clinical laboratory please indicate whether you report variants in this gene as part of your current diagnostic practice by checking the box
Standardised terms were used to represent the gene-disease mode of inheritance, and were mapped to commonly used terms from the different sources. Below each of the terms is described, along with the equivalent commonly-used terms.
A variant on one allele of this gene can cause the disease, and imprinting has not been implicated.
A variant on the paternally-inherited allele of this gene can cause the disease, if the alternate allele is imprinted (function muted).
A variant on the maternally-inherited allele of this gene can cause the disease, if the alternate allele is imprinted (function muted).
A variant on one allele of this gene can cause the disease. This is the default used for autosomal dominant mode of inheritance where no knowledge of the imprinting status of the gene required to cause the disease is known. Mapped to the following commonly used terms from different sources: autosomal dominant, dominant, AD, DOMINANT.
A variant on both alleles of this gene is required to cause the disease. Mapped to the following commonly used terms from different sources: autosomal recessive, recessive, AR, RECESSIVE.
The disease can be caused by a variant on one or both alleles of this gene. Mapped to the following commonly used terms from different sources: autosomal recessive or autosomal dominant, recessive or dominant, AR/AD, AD/AR, DOMINANT/RECESSIVE, RECESSIVE/DOMINANT.
A variant on one allele of this gene can cause the disease, however a variant on both alleles of this gene can result in a more severe form of the disease/phenotype.
A variant in this gene can cause the disease in males as they have one X-chromosome allele, whereas a variant on both X-chromosome alleles is required to cause the disease in females. Mapped to the following commonly used term from different sources: X-linked recessive.
A variant in this gene can cause the disease in males as they have one X-chromosome allele. A variant on one allele of this gene may also cause the disease in females, though the disease/phenotype may be less severe and may have a later-onset than is seen in males. X-linked inactivation and mosaicism in different tissues complicate whether a female presents with the disease, and can change over their lifetime. This term is the default setting used for X-linked genes, where it is not known definitately whether females require a variant on each allele of this gene in order to be affected. Mapped to the following commonly used terms from different sources: X-linked dominant, x-linked, X-LINKED, X-linked.
The gene is in the mitochondrial genome and variants within this can cause this disease, maternally inherited. Mapped to the following commonly used term from different sources: Mitochondrial.
Mapped to the following commonly used terms from different sources: Unknown, NA, information not provided.
For example, if the mode of inheritance is digenic, please indicate this in the comments and which other gene is involved.