rs199991156

chr5-149027810-C-Achr5-149027810-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_024577.4(SH3TC2):c.1922G>T(p.Arg641Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,556 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. R641C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SH3TC2 NM_024577.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 2.15

Genes affected

SH3TC2 (HGNC:29427): (SH3 domain and tetratricopeptide repeats 2) This gene encodes a protein with two N-terminal Src homology 3 (SH3) domains and 10 tetratricopeptide repeat (TPR) motifs, and is a member of a small gene family. The gene product has been proposed to be an adapter or docking molecule. Mutations in this gene result in autosomal recessive Charcot-Marie-Tooth disease type 4C, a childhood-onset neurodegenerative disease characterized by demyelination of motor and sensory neurons. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.744

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SH3TC2	NM_024577.4	c.1922G>T	p.Arg641Leu	missense_variant	11/17	ENST00000515425.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SH3TC2	ENST00000515425.6	c.1922G>T	p.Arg641Leu	missense_variant	11/17	1	NM_024577.4	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461556 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727094

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Charcot-Marie-Tooth disease type 4C Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Nov 12, 2020

- -

Charcot-Marie-Tooth disease type 4 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 01, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with SH3TC2-related conditions. ClinVar contains an entry for this variant (Variation ID: 907496). This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with leucine at codon 641 of the SH3TC2 protein (p.Arg641Leu). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and leucine. -

Susceptibility to mononeuropathy of the median nerve, mild Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
Cadd	Uncertain	23
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.45	T;.
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.74	D;D
MetaSVM	Uncertain	0.0070	D
MutationAssessor	Uncertain	2.5	M;.
MutationTaster	Benign	0.90	D;D;D;D
PrimateAI	Uncertain	0.54	T
PROVEAN	Pathogenic	-4.8	D;D
REVEL	Uncertain	0.56
Sift	Uncertain	0.015	D;D
Sift4G	Uncertain	0.0070	D;D
Polyphen		0.99	D;.
Vest4		0.55
MutPred		0.58		Loss of MoRF binding (P = 0.1498);.;
MVP		0.88
MPC		0.098
ClinPred		0.99	D
GERP RS		5.2
Varity_R		0.41
gMVP		0.44

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: rs199991156; hg19: chr5-148407373;