16-2060685-A-G

Position:

• chr16-2060685-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PM5 BP6

The NM_000548.5(TSC2):​c.991A>G​(p.Asn331Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,774 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N331K) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 9.11

Genes affected

TSC2 (HGNC:12363): (TSC complex subunit 2) This gene is a tumor suppressor gene that encodes the growth inhibitory protein tuberin. Tuberin interacts with hamartin to form the TSC protein complex which functions in the control of cell growth. This TSC protein complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-2060687-C-A is described in Lovd as [Pathogenic].
• BP6: Variant 16-2060685-A-G is Benign according to our data. Variant chr16-2060685-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 406128.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5	c.991A>G	p.Asn331Asp	missense_variant	11/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.991A>G	p.Asn331Asp	missense_variant	11/42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251348 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135900

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461774 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727180

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 21, 2024

The p.N331D variant (also known as c.991A>G), located in coding exon 10 of the TSC2 gene, results from an A to G substitution at nucleotide position 991. The asparagine at codon 331 is replaced by aspartic acid, an amino acid with highly similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Tuberous sclerosis 2 Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 07, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Uncertain	0.059	T
BayesDel_noAF	Benign	-0.15
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.69	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.79	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Uncertain	0.11	D
MetaRNN	Uncertain	0.63	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Benign	-0.34	T
MutationAssessor	Uncertain	2.2	M;.;.;.;M;M;.;.;.;M;.;M;.;.;.
PrimateAI	Uncertain	0.57	T
PROVEAN	Uncertain	-2.8	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Uncertain	0.41
Sift	Benign	0.046	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Uncertain	0.050	T;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		0.99	D;.;.;.;D;D;.;.;D;D;.;.;.;.;.
Vest4		0.86
MutPred		0.43		Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);.;Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);.;Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);.;
MVP		0.82
ClinPred		0.95	D
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.52
gMVP		0.54

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1060500974; hg19: chr16-2110686;