Fetal anomalies
Gene: METTL23 Red List (low evidence)Red List (low evidence)
Biallelic variants associated with syndromic ID. Published studies provide no or limited antenatal information with no consistent prenatal phenotype described.
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PMID: 32878022 – Khan et al 2020 - homozygous missense variants identified in consanguineous Pakistani family with 3 affected siblings having ID, epilepsy, behavioural issues, hypotonia and dysmorphic features (prominent large-size eyes, eyebrows, ears, short upturned nose with flat nasal bridge, and thin upper lip). Authors report that prenatal, perinatal and neonatal medical records of all patients were normal.
PMID 32439618 – Smaili et al 2020 report two Moroccan siblings presenting with mild intellectual disability and dysmorphic features. WES identified homozygous METTL23 gene variants. Describe uneventful pregnancies and postnatal course. Macrocephaly reported in both siblings (HC 52cm in a 7 year old M and 50cm in 6 yo F) - no information regarding HC of parents provided, macrocephaly not a consistently reported feature of this condition.
PMID: 32067349 – Almannai et al 2020 - 6 individuals from 4 families - 2 families unrelated, 2 families come from same Saudi tribe and are therefore likely to be distantly related with same homozygous METTL23 variant identified in both. No prenatal features or immediate postnatal issues described related to this condtion. One subject reported to have an MRI-B showing mild ventriculomegaly at a later age which may reflect mild white matter volume loss. This subject also had a 618 Kilobases duplication at 7p11.2 (57,261,112-57,878,853) identified on CGH array.
PMID: 24626631 – Bernkopf 2014 - describe 2 unrelated families. Provide no antenatal information or report no issues antenatally/at birth apart from one baby being large and cyanosed postnatally
PMID: 24501276 – Reiff et al 2014 - report 7 affected members of a large, consanguineous Arab family with ID and mild dysmorphic features. X1 patient had cleft uvula and submucosal cleft palate.
Sources: LiteratureCreated: 7 Feb 2022, 5:33 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Mental retardation, autosomal recessive 44 - #615942
Publications
Gene: mettl23 has been classified as Red List (Low Evidence).
Gene: mettl23 has been classified as Red List (Low Evidence).
gene: METTL23 was added gene: METTL23 was added to Fetal anomalies. Sources: Literature Mode of inheritance for gene: METTL23 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: METTL23 were set to 32878022; 32439618; 32067349; 24626631; 24501276 Phenotypes for gene: METTL23 were set to Mental retardation, autosomal recessive 44 - #615942 Review for gene: METTL23 was set to RED
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.