Intellectual disability - microarray and sequencing
Gene: UFC1 Amber List (moderate evidence)Comment on list classification: UFC1 identified in literature PMID:30914295 as missing in PanelApp compared to other curated gene list for ID genes. Concur with Rebecca's Amber rating, that there are currently only two distinct variants/cases UFC1.Created: 23 May 2019, 3:03 p.m.
Maddirevula et al 2019 (PMID:30237576) searched their database on exomes in search of homozygous variants that could be linked to diseases. They identified the NM_016406.3:c.317C>T:p.(Thr106Ile) variant in UFC1 in two cases with global DD and progressive microcephaly (17-3196 and 17-3892). Both of these cases were published in Nahorski et al, 2018 (PMID:29868776, Table 1).Created: 16 May 2019, 11:04 a.m.
Added 'watchlist' tag.Created: 14 May 2019, 4 p.m.
Comment on list classification: UFC1 was added to the ID panel and rated Green by Konstantinos Varvagiannis. Changed rating from Grey to Amber based on literature evidence: PMID:29868776 (Nahorski et al. 2018) identified a homozygous missense variant in the UFC1 gene (T106I) in 7 affected members of 3 consanguineous Saudi families. All members displayed Global Developmental delay. Two of the sisters were previously reported by Anazi et al. (2017, PMID:27431290). Although the Saudi families were said to be unrelated, the families shared a haplotype, suggesting a founder effect. An unrelated Swiss boy was found to have a different homozygous variant in the UFC1 gene (R23Q). There are therefore currently two distinct variants/cases. Based on the Founder effect of the three Saudi families, I have rated as Amber awaiting a further unrelated case.Created: 14 May 2019, 3:58 p.m.
Green List (high evidence)
Biallelic UFC1 mutations cause Neurodevelopmental disorder with spasticity and poor growth, MIM 618076.
PMID: 29868776 describes 7 individuals (most) born to consanguineous Saudi families (in one case the parents were not consanguineous but originated from the same tribe) as well as a further individual born to distantly related Swiss parents. One of these patients was previously briefly published by the same authors (PMID: 27431290).
The phenotype consisted of developmental delay (8/8 - usually profound), failure to thrive (8/8), short stature and microcephaly (both observed in 7/8), seizures (4/8) and variable brain MRI anomalies in some of these subjects.
Overall, two UFC1 missense variants are reported [NM_016406.3:c.317C>T or p.(Thr106Ile) and c.68G>A or p.(Arg23Gln) the former in the Saudi individuals]. Functional studies demonstrated the hypomorphic nature of the variants.
UFC1 (as well as UFM1 also discussed in the same article) participate in ufmylation, with mutations in other enzymes of the same process (notably UBA5 - gene rated Green in the ID and epilepsy panels) having already been described in neurodevelopmental disorders.
As a result this gene can be considered for inclusion in the ID panel as green (or amber).
Sources: Literature, Expert ReviewCreated: 20 Nov 2018, 10:29 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Neurodevelopmental disorder with spasticity and poor growth, 618076
Publications
Added phenotypes Neurodevelopmental disorder with spasticity and poor growth, 618076 for gene: UFC1 Publications for gene UFC1 were changed from 29868776; 27431290; 30237576 to 30914295
Phenotypes for gene: UFC1 were changed from Neurodevelopmental disorder with spasticity and poor growth, 618076 to Neurodevelopmental disorder with spasticity and poor growth, 618076; global developmental delay with progressive microcephaly
Publications for gene: UFC1 were set to 29868776; 27431290
Tag watchlist tag was added to gene: UFC1.
Gene: ufc1 has been classified as Amber List (Moderate Evidence).
Publications for gene: UFC1 were set to 29868776
gene: UFC1 was added gene: UFC1 was added to Intellectual disability. Sources: Literature,Expert Review Mode of inheritance for gene: UFC1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: UFC1 were set to 29868776 Phenotypes for gene: UFC1 were set to Neurodevelopmental disorder with spasticity and poor growth, 618076 Penetrance for gene: UFC1 were set to Complete Review for gene: UFC1 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.