Intellectual disability - microarray and sequencing
Gene: KMT2E Green List (high evidence)Comment on publications: PMID: 34321323 - 18 additional patients from 17 families with genetically confirmed ODLUROCreated: 1 Sep 2021, 4:18 p.m. | Last Modified: 1 Sep 2021, 4:18 p.m.
Panel Version: 3.1250
Comment on phenotypes: added OMIM MIM idCreated: 19 Aug 2019, 9:54 a.m. | Last Modified: 19 Aug 2019, 9:54 a.m.
Panel Version: 2.1014
Comment on list classification: Sufficient cases with ID to rate green.Created: 13 Jun 2019, 11:05 a.m.
Not associated with any phenotype in OMIM. Confirmed association with Intellectual disability in Gene2Phenotype (monoallelic)
PMID: 31079897 O'Donnell-Luria et al 2019 - report on additional 35 individuals with heterozygous variants in KMT2E and 3 previously reported males. New cases were ascertained from GeneMatcher through the Matchmaker Exchange Network and MyGene2. 34 individuals from 32 families were found to have single-nucleotide or indel variants in KMT2E, and four additional individuals had copy-number variants encompassing KMT2E. 21 unrelated individuals reported with mild to severe intellectual disability (2 severe, 5 moderate).
Sufficient cases with likely disease-causing variants to rate as green.Created: 13 Jun 2019, 11:02 a.m.
Green List (high evidence)
In a collaborative study, O'Donnell-Luria et al. (2019 - https://doi.org/10.1101/566091 - DDD study among the co-authors) report on 38 individuals from 36 families with heterozygous KMT2E variants. Some of these individuals were previously included in previous publications.
Developmental delay, intellectual disability, epilepsy and ASD were among the features reported, albeit of variable degree and not universal.
34 of 38 individuals had SNVs or indel variants in KMT2E and 4 individuals had CNVs spanning KMT2E (in one case intragenic, in 3 further as a contiguous gene deletion).
For 26 (of 38 individuals) the variant had arisen as a de novo event while in some cases parental sample(s) was/were unavailable to confirm the de novo occurrence or origin (from a reportedly affected parent). The variant in one family was inherited from a parent for whom information on affected/unaffected status was unavailable.
As for the variants reported: 30 were protein-truncating (of which 23 predicted to produce transcripts subject to NMD). 4 were missense. 4 were CNVs (de novo deletions, of which 1 intragenic).
Truncating variants and deletions of KMT2E suggest haploinsufficiency as the underlying mechanism for this category of variants (KMT2E has a pLI of 1 in gnomAD).
However, the somewhat different phenotype related to missense variants (degree of ID, epilepsy in all, microcephaly in some versus macrocephaly in subjects with truncating variants) may suggest a different mechanism for these variants eg. gain of function or dominant negative effect. There was no clustering observed for the missense variants reported.
Expressivity of certain features may be variable between males and females.
As the authors note : KMT2E encodes a member of the lysine N-methyltransferase 2 family, a family of enzymes with critical role in H3K4 methylation. It is highly expressed in brain, particularly during fetal development. Several monogenic neurodevelopmental disorders due to impaired regulation of H3K4 methylation are known (eg. due to KMT2D/C/B/A mutations, etc). Studies suggest that KMT2E may lack intrinsic methyltransferase activity although it may have an indirect effect on H3K4 methylation. In contrast to other members of the KMT2 family functioning as global activators of open chromatin, KMT2E is believed to be a repressor (although it's function in gene transcription regulation needs to be clarified).
A neurological phenotype of Kmt2e (Mll5) deficiency mouse models has not been reported (features included growth restriction, impaired hematopoiesis, etc).
KMT2E is not associated with any phenotype in OMIM. The gene is included in the DD panel of G2P, associated with Intellectual disability (disease confidence: confirmed / mutation consequence registered in the db : LoF).
KMT2E is included in gene panels for ID offered by some diagnostic laboratories (eg. among those participating in the study).
As a result, this gene can be considered for upgrade to green (or amber).Created: 17 Mar 2019, 10:12 a.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Phenotypes
Global developmental delay; Intellectual disability; Autism; Seizures; Abnormality of skull size
Publications
Variants in this GENE are reported as part of current diagnostic practice
Publications for gene: KMT2E were set to 31079897
Phenotypes for gene: KMT2E were changed from Global developmental delay; Intellectual disability; Autism; Seizures; Abnormality of skull size to O'Donnell-Luria-Rodan syndrome, 618512; Global developmental delay; Intellectual disability; Autism; Seizures; Abnormality of skull size
Phenotypes for gene: KMT2E were changed from to Global developmental delay; Intellectual disability; Autism; Seizures; Abnormality of skull size
Gene: kmt2e has been classified as Green List (High Evidence).
Publications for gene: KMT2E were set to 31079897
Publications for gene: KMT2E were set to
Mode of inheritance for gene: KMT2E was changed from to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
gene: KMT2E was added gene: KMT2E was added to Intellectual disability. Sources: Victorian Clinical Genetics Services Mode of inheritance for gene: KMT2E was set to
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.