Fetal anomalies
Gene: MYT1 Green List (high evidence)Green List (high evidence)
This gene and phenotype were reviewed during meetings at Great Ormond Street hospital in March and April 2019. Clinical review and curation was performed by Lyn Chitty, Anna de Burca, Rhiannon Mellis, Richard Scott, Ellen McDonagh and Rebecca Foulger. Outcome of review: Confirmed that phenotype is fetally-relevant: include on the Fetal anomalies panel as a Green gene. Additional notes from clinical review: There is no disorder in OMIM assocaited with MYT1, but Oculo-auriculo-vertebral spectrum (OAVS, also called Goldenhar) is described in two papers from same group- PMID:28612832 and PMID:27358179. There are 3 MYT1 variants from these 2 papers (2 missense, 1 nonsense) in OAVS patients so just meets evidence threshold. Caution was taken given the genetic heterogeneity and non-genetic factors associated with OAVS/Goldenhar. However on balance it was decided that the 3 literature variants are sufficient evidence for inclusion of MYT1 on the Fetal anomalies panel.Created: 29 Apr 2019, 2:52 p.m.
Berenguer et al 2017 (PMID:28612832) identified a third (de novo) MYT1 variant in a patient with OAVS: c.323C>T p.Ser108Leu from a cohort of 57 new patients with a typically heterogeneous OAVS. From functional studies, it's still unclear how these variants impact retinoic acid signaling and contribute to the phenotype.Created: 25 Apr 2019, 2:58 p.m.
Lopez et al 2016 (PMID:27358179) identified a heterozgous MYT1 de novo nonsense variant in one patient (c.25C>T, p.Arg9*) and one heterozygous inherited missense variant in second patient (c.314C>T, p.Ser105Leu) in a cohort of 169patients with OAVS. Functional studies by transient knockdown of myt1a in zebrafish, led to specific craniofacial cartilage alterations.Created: 25 Apr 2019, 2:58 p.m.
Oculo-auriculo-vertebral spectrum (OAVS) is a developmental disorder characterized by hemifacial microsomia associated with ear, eyes and vertebrae malformations showing highly variable expressivity (PMID:28612832).Created: 25 Apr 2019, 2:58 p.m.
MYT1 is not currently associated with a disorder in OMIM (April 2019) but there are two publications (PMID:28612832 and PMID:27358179) describing three separate variants in three patients with OAVS.Created: 25 Apr 2019, 9:42 a.m.
MYT1 was added to the panel as Amber based on a 'Probable' rating in the Additional Gene list supplied by the PAGE group. Note that 'OAVS/Goldenhar syndrome' currently has a 'possible' rating in DD-G2P with Allelic requirement:monoallelic, and Mutation consequence summary:loss of function.Created: 7 Mar 2019, 11:51 a.m.
Rating in original (Additional gene list) PAGE list: Probable. Original mode of inheritance: monoallelic. Original mode of pathogenicity: uncertain.Created: 11 Dec 2018, 9:05 a.m.
In the original PAGE file, MOP listed as Uncertain.Created: 8 Nov 2018, 4:45 p.m.
Publications
Mode of pathogenicity
Other - please provide details in the comments
Tag gene-checked tag was added to gene: MYT1.
Mode of pathogenicity for gene: MYT1 was changed from to Other
Source Expert Review Green was added to MYT1. Publications for gene MYT1 were changed from 28612832; 27358179 to 27358179; 28612832 Rating Changed from Amber List (moderate evidence) to Green List (high evidence)
Publications for gene: MYT1 were set to 28612832
Phenotypes for gene: MYT1 were changed from Oculo-auriculo-vertebral spectrum (OAVS) to Oculo-auriculo-vertebral spectrum (OAVS); OAVS/Goldenhar syndrome
gene: MYT1 was added gene: MYT1 was added to Fetal anomalies. Sources: PAGE Additional Gene List,Expert Review Amber Mode of inheritance for gene: MYT1 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: MYT1 were set to 28612832 Phenotypes for gene: MYT1 were set to Oculo-auriculo-vertebral spectrum (OAVS)
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.