chr16-2054405-A-G
Variant summary
Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BS2
The NM_000548.5(TSC2):c.446A>G(p.Asn149Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,614,098 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N149D) has been classified as Uncertain significance.
Frequency
Consequence
NM_000548.5 missense
Scores
Clinical Significance
Conservation
Publications
- tuberous sclerosisInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- tuberous sclerosis 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics
- lymphangioleiomyomatosisInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- tuberous sclerosis complexInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152212Hom.: 0 Cov.: 33 show subpopulations
GnomAD4 exome AF: 0.00000342 AC: 5AN: 1461886Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2AN XY: 727246 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152212Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74368 show subpopulations
ClinVar
Submissions by phenotype
Tuberous sclerosis 2 Uncertain:2
This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 149 of the TSC2 protein (p.Asn149Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TSC2-related conditions. ClinVar contains an entry for this variant (Variation ID: 480817). 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) indicates that this missense variant is not expected to disrupt TSC2 protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
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not specified Uncertain:1
Variant summary: TSC2 c.446A>G (p.Asn149Ser) results in a conservative amino acid change located in the Tuberin, N-terminal domain (IPR024584) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251492 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.446A>G in individuals affected with Tuberous Sclerosis Complex and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 480817). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Tuberous sclerosis syndrome Uncertain:1
This missense variant replaces asparagine with serine at codon 149 of the TSC2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TSC2-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 18466115) -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.N149S variant (also known as c.446A>G), located in coding exon 4 of the TSC2 gene, results from an A to G substitution at nucleotide position 446. The asparagine at codon 149 is replaced by serine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at