Intellectual disability - microarray and sequencing
Gene: ARF1 Green List (high evidence)Comment on publications: PMID:36345169 reported a paediatric patient identified with a monoallelic de novo missense variant (c.296 G > A; p.R99H) in the ARF1 gene, associated with developmental delay, hypotonia, intellectual disability and motor stereotypies. This patient did not exhibit periventricular heterotopias previously observed in other patients with ARF1 variants (including p.R99H). Functional analysis shows that the pathogenetic mechanism of the R99H-ARF1 variant involves constitutive activation with resultant Golgi and endosomal alterations.Created: 23 Mar 2023, 5:03 p.m. | Last Modified: 23 Mar 2023, 5:03 p.m.
Panel Version: 5.5
Comment on publications: PMID:36345169 reported a paediatric patient identified with a monoallelic de novo missense variant (c.296 G > A; p.R99H) in the ARF1 gene, associated with developmental delay, hypotonia, intellectual disability and motor stereotypies. This patient did not exhibit periventricular heterotopias previously observed in other patients with ARF1 variants (including p.R99H). Functional analysis shows that the pathogenetic mechanism of the R99H-ARF1 variant involves constitutive activation with resultant Golgi and endosomal alterations.Created: 23 Mar 2023, 5:02 p.m. | Last Modified: 23 Mar 2023, 5:02 p.m.
Panel Version: 5.5
Comment on publications: PMID:36345169 reported a paediatric patient identified with a monoallelic de novo missense variant (c.296 G > A; p.R99H) in the ARF1 gene, associated with developmental delay, hypotonia, intellectual disability and motor stereotypies. This patient did not exhibit periventricular heterotopias previously observed in other patients with ARF1 variants (including p.R99H). Functional analysis shows that the pathogenetic mechanism of the R99H-ARF1 variant involves constitutive activation with resultant Golgi and endosomal alterations.Created: 23 Mar 2023, 5:02 p.m. | Last Modified: 23 Mar 2023, 5:02 p.m.
Panel Version: 5.4
Comment on publications: PMID:36345169 reported a paediatric patient identified with a monoallelic de novo missense variant (c.296 G > A; p.R99H) in the ARF1 gene, associated with developmental delay, hypotonia, intellectual disability and motor stereotypies. This patient did not exhibit periventricular heterotopias previously observed in other patients with ARF1 variants (including p.R99H). Functional analysis shows that the pathogenetic mechanism of the R99H-ARF1 variant involves constitutive activation with resultant Golgi and endosomal alterations.Created: 23 Mar 2023, 5:02 p.m. | Last Modified: 23 Mar 2023, 5:02 p.m.
Panel Version: 5.4
The rating of this gene has been updated following NHS Genomic Medicine Service approval.Created: 14 Mar 2022, 2:22 p.m. | Last Modified: 14 Mar 2022, 2:22 p.m.
Panel Version: 3.1519
Green List (high evidence)
Added to ID panel as developmental delay (especially in speech) is a reported feature in all cases (except for one individuals for which only limited clinical information was available). Although only one patient has been reported with a moderate ID diagnosis, developmental delay is likely to be noticed earlier in the course of disease than cortical malformations and may prompt genetic investigation. Inclusion on this panel could increase the likelihood of detecting cases and therefore a Green rating is warranted.Created: 3 Sep 2021, 2:38 p.m. | Last Modified: 3 Sep 2021, 2:38 p.m.
Panel Version: 3.1252
Comment on publications: Gana et al., 2021 (PMID: 34353862) - additional family identified with a 5-year-old girl who inherited a heterozygous nonsense variant in the ARF1 gene (c.234G>A; p.Trp78Ter) from her father. Both displayed periventricular nodular heterotopia on brain MRI but with milder clinical expression in the father.Created: 3 Sep 2021, 2:24 p.m. | Last Modified: 3 Sep 2021, 2:24 p.m.
Panel Version: 2.62
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Periventricular nodular heterotopia 8, OMIM:618185
Publications
Comment on list classification: New gene added by Zornitza Stark (Australian Genomics). This gene is associated with a relevant phenotype in OMIM and Gene2Phenotype. There is enough evidence to support a gene-disease association. This gene should be rated Green at the next review.Created: 17 Aug 2021, 1:42 p.m. | Last Modified: 17 Aug 2021, 1:42 p.m.
Panel Version: 2.55
Green List (high evidence)
Three unrelated individuals reported with de novo missense in this gene.
Sources: Expert listCreated: 24 Aug 2020, 11:02 a.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Periventricular nodular heterotopia 8, MIM# 618185
Publications
Variants in this GENE are reported as part of current diagnostic practice
Publications for gene: ARF1 were set to 28868155; 34353862; 36345169
Publications for gene: ARF1 were set to 28868155; 34353862; 36345169
Publications for gene: ARF1 were set to 28868155; 34353862; 36345169
Publications for gene: ARF1 were set to 28868155; 34353862
Tag Q3_21_rating was removed from gene: ARF1.
Source Expert Review Green was added to ARF1. Rating Changed from Amber List (moderate evidence) to Green List (high evidence)
gene: ARF1 was added gene: ARF1 was added to Intellectual disability. Sources: Expert list,Expert Review Amber Q3_21_rating tags were added to gene: ARF1. Mode of inheritance for gene: ARF1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: ARF1 were set to 28868155; 34353862 Phenotypes for gene: ARF1 were set to Periventricular nodular heterotopia 8, OMIM:618185
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.