Mendeliome
Gene: DACT1 Amber List (moderate evidence)I don't know
PMID 36066768 identified 7 different heterozygous missense variants in 8 individuals with renal abnormalities. 6 also had extrarenal anomalies which the authors claimed overlapped Townes-Brookes syndrome. Parents were tested in 7/8 families and all variants were inherited. One family was consanguineous and both parents were carriers. All variant-positive parents were either unaffected or unknown affected status, except for one who had skeletal abnormalities. Gnomad het counts range from novel (3 variants) to 89 hets. 2 variants are LB in ClinVar, athough the authors have classified them as LP and VUS.Created: 6 Oct 2022, 4:06 a.m. | Last Modified: 6 Oct 2022, 4:06 a.m.
Panel Version: 1.369
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Phenotypes
Townes-Brocks syndrome 2 MONDO:0054582
Publications
Variants in this GENE are reported as part of current diagnostic practice
Red List (low evidence)
Webb et al. (2017) reported 6 affected members of a 3-generation family with ?Townes-Brocks syndrome-2, identified heterozygosity for a nonsense mutation in the DACT1 gene that segregated with disease. Clinical features include imperforate anus, rectovaginal fistula, crossed fused renal ectopia, vesicoureteral reflux, unilateral microtia, overfolded helices and cupped ears. One family member (proband's mother) with scoliosis and spina bifida occulta. Neural tube defects reported in a study of human fetuses (PMID: 22610794) and a mouse model (PMID: 19701191). Listed in Decipher v10.0 for an individual with abnormalities of (i) head or neck (ii) nervous system (iii) skeletal system. Unlike the gene SALL1 that causes Townes-Brocks syndrome 1, there is no information specifically relating to DACT1 with radial dysplasia, as these were not observed in the family with ?Townes-Brocks syndrome 2 (PMID: 28054444).
Sources: NHS GMSCreated: 22 Jul 2020, 6:47 a.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
?Townes-Brocks syndrome 2 (OMIM #617466)
Publications
Gene: dact1 has been classified as Amber List (Moderate Evidence).
Gene: dact1 has been classified as Red List (Low Evidence).
Phenotypes for gene: DACT1 were changed from ?Townes-Brocks syndrome 2 (OMIM #617466) to Townes-Brocks syndrome 2 (OMIM #617466)
Gene: dact1 has been classified as Red List (Low Evidence).
gene: DACT1 was added gene: DACT1 was added to Mendeliome. Sources: NHS GMS Mode of inheritance for gene: DACT1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: DACT1 were set to PMID: 28054444; 22610794; 19701191 Phenotypes for gene: DACT1 were set to ?Townes-Brocks syndrome 2 (OMIM #617466) Review for gene: DACT1 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.