chr16-2072899-C-A

Variant names:

• chr16-2072899-C-A
• rs1555506918
• NM_000548.5:c.2271C>A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000548.5(TSC2):​c.2271C>A​(p.Phe757Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.930

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.2271C>A	p.Phe757Leu	missense_variant	Exon 21 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.2271C>A	p.Phe757Leu	missense_variant	Exon 21 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Feb 13, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TSC2 c.2271C>A (p.Phe757Leu) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251070 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.2271C>A in individuals affected with Tuberous Sclerosis Complex and no experimental evidence demonstrating its impact on protein function have been reported. No submitters have cited clinical-significance assessments for this variant to ClinVar. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.88
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.030
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.71	D;.;.;.;.;.;.;.;.;.;.;.;D;.;D
Eigen	Benign	0.18
Eigen_PC	Benign	0.21
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.79	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Uncertain	0.18	D
MetaRNN	Uncertain	0.47	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.16	T
MutationAssessor	Benign	0.91	L;.;.;.;L;L;.;.;.;L;.;L;.;.;.
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-2.5	N;.;.;D;.;N;.;.;D;N;.;.;.;.;N
REVEL	Uncertain	0.58
Sift	Benign	0.095	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Pathogenic	0.0	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		0.98	D;.;.;.;D;P;.;.;D;P;.;.;.;.;.
Vest4		0.56
MutPred		0.50		Gain of disorder (P = 0.1108);Gain of disorder (P = 0.1108);Gain of disorder (P = 0.1108);.;Gain of disorder (P = 0.1108);Gain of disorder (P = 0.1108);Gain of disorder (P = 0.1108);Gain of disorder (P = 0.1108);.;Gain of disorder (P = 0.1108);Gain of disorder (P = 0.1108);Gain of disorder (P = 0.1108);Gain of disorder (P = 0.1108);Gain of disorder (P = 0.1108);.;
MVP		0.66
ClinPred		0.75	D
GERP RS		3.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.21
gMVP		0.53

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1555506918; hg19: chr16-2122900;