Intellectual disability - microarray and sequencing
Gene: NEMF Green List (high evidence)The rating of this gene has been updated following NHS Genomic Medicine Service approval.Created: 9 Mar 2022, 3:40 p.m. | Last Modified: 9 Mar 2022, 3:40 p.m.
Panel Version: 3.1510
Green List (high evidence)
Comment on list classification: Rating Amber but there is sufficient evidence to promote to Green at the next GMS panel update (added 'for-review' tag)Created: 3 Nov 2020, 11:45 a.m. | Last Modified: 3 Nov 2020, 11:45 a.m.
Panel Version: 3.507
Comment on mode of inheritance: Set MOI to 'Biallelic' as currently only 1 case (total 14) with a monoallelic variant described but with normal intellectual development.Created: 3 Nov 2020, 11:42 a.m. | Last Modified: 3 Nov 2020, 11:42 a.m.
Panel Version: 3.505
At least 14 unrelated families reported with variants in NEMF (13 biallelic, 1 monoallelic). GDD/ID is reported in all but 2 cases (USA1 and USA3 in PMID: 32934225) albeit mostly within the mild range. Nonetheless, there are sufficient cases with moderate-severe ID to warrant a Green rating on this panel. Some cases also do not present all other features associated with NEMF variants (e.g. neuropathy) providing further support for inclusion.Created: 3 Nov 2020, 11:35 a.m. | Last Modified: 3 Nov 2020, 11:35 a.m.
Panel Version: 3.504
Currently not associated with any phenotype in OMIM (last edited on 04/01/2017) or Gene2Phenotype.
- PMID: 33048237 (2020) - 13 affected individuals from 5 unrelated families presenting with a spectrum of central (speech delay (12/13), intellectual disability (13/13), abnormal eye movement, scoliosis) and peripheral (axonal neuropathy, lower limb hypotonia) neurological involvement. Degree of ID was mild to moderate in families 1-4, while the patient in family 5 displayed severe cognitive delay. Knockdown studies in cultured mouse primary cortical neurons showed a significant decrease in axon length and impaired synapse development.
PMID: 27431290 (2017) - 3 individuals from 2 unrelated families with different homozygous truncating variants in NEMF and non-syndromic ID. Assessment of the two sibs indicated severe ID. Details are limited regarding the other individual but developmental delay was noted with an inability to speak at 4 years.Created: 3 Nov 2020, 11:14 a.m. | Last Modified: 3 Nov 2020, 11:14 a.m.
Panel Version: 3.504
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Publications
Green List (high evidence)
Martin et al (2020 - PMID:32934225) report on 8 individuals from 6 families with a juvenile neuromuscular disease due to biallelic NEMF variants. (In one of these 8 cases it could not be ruled out that a de novo and maternally inherited variant were on the same allele, as phase was not determined). A ninth individual with similar presentation was found to harbor a single NEMF missense SNV as de novo event (due to a speculated dominant-negative effect). This individual had a similar presentation.
Features incl. hypotonia (4/8 with biallelic variant (B) | 1/1 monoallelic (M) ), DD/ID (7/8B | 0/1M) with speech delay as universal feature (8/8B | 1/1M), axonal neuropathy (3/3B | 1/1M), ataxia (3/8B | 0/1M). Other findings included tremor (1/7B | 1/1M), abnormal brain imaging (2/6B / ?/1M), kyphosis/scoliosis (4/8B | 0/1M), respiratory distress (1/8B | 0/1M).
NEMF (Rqc2 in yeast) encodes the nuclear export mediator factor, a component of the Ribosome-associated Quality Control (RCQ) complex which is involved in proteolytic targeting of incomplete polypeptides produced by ribosome stalling. NEMF facilitates the recruitment of E3 ligase Listerin (LTN1) which ubiquitinates nascent polypeptide chains for subsequent proteasomal degradation.
The author provide evidence that mice homozygous for Nemf missense mutations display progressive motor phenotypes, exhibit neurogenic atrophy and progressive axonal degeneration. A further NEMF-null mouse model displayed more severe phenotype (with heterozygous mice being unaffected).
Equivalent mutations (of those in the above mouse model) in yeast (Rqc2) were shown to interfere with its ability to modify aberrant translation products with C-terminal tails which assist RQC-mediated protein degradation.
Mutation of Ltn1 (belonging to the same protein control pathway) has been also shown to lead to neurodegeneration in mice.
Overall NEMF is thought to play a role in neuronal translational homeostasis and the disorder to be mediated by dysfunction of the RQC pathway (normally protecting neurons against degeneration).
Sources: LiteratureCreated: 3 Oct 2020, 8:16 p.m. | Last Modified: 3 Oct 2020, 8:31 p.m.
Panel Version: 3.369
Mode of inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Phenotypes
Hypotonia; Global developmental delay; Intellectual disability; Axonal neuropathy; Ataxia; Abnormal brain imaging; Kyphosis; Scoliosis; Tremor; Respiratory distress
Publications
Tag for-review was removed from gene: NEMF.
Source Expert Review Green was added to NEMF. Rating Changed from Amber List (moderate evidence) to Green List (high evidence)
Gene: nemf has been classified as Amber List (Moderate Evidence).
Publications for gene: NEMF were set to 32934225
Mode of inheritance for gene: NEMF was changed from BOTH monoallelic and biallelic, autosomal or pseudoautosomal to BIALLELIC, autosomal or pseudoautosomal
Tag for-review tag was added to gene: NEMF.
gene: NEMF was added gene: NEMF was added to Intellectual disability. Sources: Literature Mode of inheritance for gene: NEMF was set to BOTH monoallelic and biallelic, autosomal or pseudoautosomal Publications for gene: NEMF were set to 32934225 Phenotypes for gene: NEMF were set to Hypotonia; Global developmental delay; Intellectual disability; Axonal neuropathy; Ataxia; Abnormal brain imaging; Kyphosis; Scoliosis; Tremor; Respiratory distress Penetrance for gene: NEMF were set to Complete Review for gene: NEMF was set to GREEN
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 [email protected]
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.