rs370916731
Variant summary
Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6
The NM_000368.5(TSC1):c.899C>T(p.Thr300Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,614,082 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000368.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -1 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
TSC1 | ENST00000298552.9 | c.899C>T | p.Thr300Ile | missense_variant | Exon 9 of 23 | 1 | NM_000368.5 | ENSP00000298552.3 | ||
TSC1 | ENST00000490179.4 | c.899C>T | p.Thr300Ile | missense_variant | Exon 10 of 24 | 3 | ENSP00000495533.2 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152236Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251256Hom.: 0 AF XY: 0.00000737 AC XY: 1AN XY: 135766
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1461846Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 727220
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152236Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74378
ClinVar
Submissions by phenotype
Tuberous sclerosis 1 Uncertain:1Benign:2
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A TSC1 c.899C>T (p.Thr300Ile) variant was identified at a heterozygous allelic fraction of 49%, a frequency consistent with germline origin. This variant, to our knowledge, has not been reported in the medical literature and is only observed on 3/780,974 alleles in the general population (gnomAD v.4.0.0), indicating it is not a common variant. This variant has been reported in the ClinVar database by four submitters (ClinVar ID: 411242), but with conflicting interpretations. Computational predictors are uncertain as to the impact of this variant on TSC1 function. Due to limited and conflicting information, and based on ACMG/AMP guidelines for variant interpretation (Richards S et al., PMID: 25741868), the clinical significance of the TSC1 c.899C>T (p.Thr300Ile) variant is uncertain at this time. -
Tuberous sclerosis syndrome Uncertain:1
This missense variant replaces threonine with isoleucine at codon 300 of the TSC1 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 hereditary cancer in the literature. This variant has been identified in 1/251256 chromosomes 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. -
Isolated focal cortical dysplasia type II Uncertain:1
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Hereditary cancer-predisposing syndrome Uncertain:1
The p.T300I variant (also known as c.899C>T), located in coding exon 7 of the TSC1 gene, results from a C to T substitution at nucleotide position 899. The threonine at codon 300 is replaced by isoleucine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at