rs747538224
Variant summary
Our verdict is Likely pathogenic. The variant received 9 ACMG points: 10P and 1B. PM1PP5_Very_StrongBP4
The NM_001199107.2(TBC1D24):c.845C>G(p.Pro282Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000328 in 1,613,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P282S) has been classified as Uncertain significance.
Frequency
Consequence
NM_001199107.2 missense
Scores
Clinical Significance
Conservation
Publications
- DOORS syndromeInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, PanelApp Australia, G2P
- familial infantile myoclonic epilepsyInheritance: AR Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Orphanet
- autosomal dominant nonsyndromic hearing loss 65Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
- autosomal dominant nonsyndromic hearing lossInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- malignant migrating partial seizures of infancyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- focal epilepsy-intellectual disability-cerebro-cerebellar malformationInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hearing loss, autosomal recessiveInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- progressive myoclonic epilepsy with dystoniaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- nonsyndromic genetic hearing lossInheritance: AD Classification: LIMITED Submitted by: ClinGen
- autosomal recessive nonsyndromic hearing loss 86Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 9 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| TBC1D24 | ENST00000646147.1 | c.845C>G | p.Pro282Arg | missense_variant | Exon 2 of 8 | NM_001199107.2 | ENSP00000494678.1 | |||
| ENSG00000260272 | ENST00000564543.1 | c.845C>G | p.Pro282Arg | missense_variant | Exon 1 of 3 | 2 | ENSP00000455547.1 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152276Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.000176 AC: 44AN: 249376 AF XY: 0.000118 show subpopulations
GnomAD4 exome AF: 0.0000342 AC: 50AN: 1461606Hom.: 0 Cov.: 31 AF XY: 0.0000275 AC XY: 20AN XY: 727134 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152276Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74398 show subpopulations
ClinVar
Submissions by phenotype
not provided Pathogenic:3
Reported previously in individuals with clinical features consistent with TBC1D24-related DOORS spectrum disorder who also harbored a second TBC1D24 variant (PMID: 27502353, 27281533); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 27281533, 31440721, 29100083, 33281559, 27502353, 34926809) -
The p.Pro282Arg variant in the TBC1D24 gene has been previously reported in at least 17 unrelated individuals with seizures and developmental delay, and co-segregated with disease in at least 3 affected relatives from 3 families (Appavu et al., 2016; GeneDx, personal communication, March 2, 2020; Hamdan et al., 2017; Invitae, personal communication, February 12, 2020). All affected individuals were homozygous or compound heterozygous. This variant was determined to be in trans with at least 4 different likely pathogenic or pathogenic variants consistent with autosomal recessive inheritance (GeneDx, personal communication, March 2, 2020; Hamdan et al., 2017; Invitae, personal communication, February 12, 2020). The presence of this variant with a diseaseassociated variant on the opposite allele increases suspicion for its pathogenicity. The p.Pro282Arg variant has also been identified in 45/35,374 Latino chromosomes by the Genome Aggregation Database (http://gnomad.broadinstitute.org/). Computational tools predict that this variant is deleterious; however, the accuracy of in silico algorithms is limited. These data were assessed using the ACMG/AMP variant interpretation guidelines. In summary, there is sufficient evidence to classify the p.Pro282Arg variant as pathogenic for autosomal recessive TBC1D24-associated disorders based on the information above. [ACMG evidence codes used: PM2; PM3_verystrong; PP1_moderate; PP3] -
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Inborn genetic diseases Pathogenic:1
The c.845C>G (p.P282R) alteration is located in exon 2 (coding exon 1) of the TBC1D24 gene. This alteration results from a C to G substitution at nucleotide position 845, causing the proline (P) at amino acid position 282 to be replaced by an arginine (R). Based on data from the Genome Aggregation Database (gnomAD), the TBC1D24 c.845C>G alteration was observed in 0.02% (46/280780) of total alleles studied, with a frequency of 0.13% (45/35374) in the Latino subpopulation. This variant has been reported in the compound heterozygous state in three individuals with epilepsy (Appavu, 2016; Balestrini, 2016; Hamdan, 2017). The in silico prediction for the p.P282R alteration is inconclusive. Based on the available evidence, this alteration is classified as likely pathogenic. -
DOORS syndrome Pathogenic:1
This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. -
Developmental and epileptic encephalopathy, 1;C3892048:Autosomal dominant nonsyndromic hearing loss 65;CN236805:Caused by mutation in the TBC1 domain family, member 24 Pathogenic:1
This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 282 of the TBC1D24 protein (p.Pro282Arg). This variant is present in population databases (rs747538224, gnomAD 0.1%). This missense change has been observed in individual(s) with autosomal recessive epileptic encephalopathy (PMID: 27502353, 29100083; internal data). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 207505). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on TBC1D24 protein function. For these reasons, this variant has been classified as Pathogenic. -
developmental delay with seizures Uncertain:1
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not specified Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at