5-149008949-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBS1_SupportingBS2

The NM_024577.4(SH3TC2):c.3380G>A(p.Arg1127Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00197 in 1,614,198 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign outcome for this variant. 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. R1127W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0010 ( 1 hom., cov: 32)

Exomes 𝑓: 0.0021 ( 6 hom. )

Consequence

SH3TC2
NM_024577.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:10B:4

Conservation

PhyloP100: 7.45

Publications

7 publications found

Variant links:

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]

SH3TC2 Gene-Disease associations (from GenCC):

autosomal recessive hereditary demyelinating motor and sensory neuropathy
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
Charcot-Marie-Tooth disease type 4C
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics
susceptibility to mononeuropathy of the median nerve, mild
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

SH3TC2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.16030511).

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.00102 (155/152306) while in subpopulation NFE AF = 0.00201 (137/68030). AF 95% confidence interval is 0.00174. There are 1 homozygotes in GnomAd4. There are 74 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High Homozygotes in GnomAdExome4 at 6 AR,AD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SH3TC2	NM_024577.4 link	c.3380G>A	p.Arg1127Gln	missense_variant	Exon 15 of 17	ENST00000515425.6	NP_078853.2	Q8TF17-1A0A514TP98

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SH3TC2	ENST00000515425.6 link	c.3380G>A	p.Arg1127Gln	missense_variant	Exon 15 of 17	1	NM_024577.4	ENSP00000423660.1		Q8TF17-1

Frequencies

GnomAD3 genomes

AF:

0.00102

AC:

155

AN:

152188

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000314

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00201

Gnomad OTH

AF:

0.000957

GnomAD2 exomes

AF:

0.000942

AC:

237

AN:

251480

AF XY:

0.00103

show subpopulations

Gnomad AFR exome

AF:

0.000246

Gnomad AMR exome

AF:

0.000318

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00190

Gnomad OTH exome

AF:

0.000814

GnomAD4 exome

AF:

0.00206

AC:

3017

AN:

1461892

Hom.:

Cov.:

AF XY:

0.00196

AC XY:

1422

AN XY:

727248

show subpopulations

African (AFR)

AF:

0.000269

AC:

AN:

33480

American (AMR)

AF:

0.000358

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.000131

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00261

AC:

2907

AN:

1112010

Other (OTH)

AF:

0.00123

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.473

Heterozygous variant carriers

185

370

556

741

926

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

118

236

354

472

590

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00102

AC:

155

AN:

152306

Hom.:

Cov.:

AF XY:

0.000994

AC XY:

AN XY:

74482

show subpopulations

African (AFR)

AF:

0.000313

AC:

AN:

41554

American (AMR)

AF:

0.000196

AC:

AN:

15306

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00201

AC:

137

AN:

68030

Other (OTH)

AF:

0.000947

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.499

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00156

Hom.:

Bravo

AF:

0.000971

TwinsUK

AF:

0.00324

AC:

ALSPAC

AF:

0.00234

AC:

ESP6500AA

AF:

0.000454

AC:

ESP6500EA

AF:

0.00221

AC:

ExAC

AF:

0.000898

AC:

109

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.00136

EpiControl

AF:

0.00219

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:10Benign:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:4

Dec 23, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Reported in the heterozygous state in three individuals with symptoms of CMT1 and was described as being a variant of unknown significance (PMID: 26392352); Identified in patients with suspected Charcot-Marie-Tooth disease; however, no further clinical or segregation information was provided (PMID: 32376792); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26872463, 27535533, 32376792, 26392352) -

Jul 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Dec 16, 2020

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The SH3TC2 c.3380G>A; p.Arg1127Gln variant (rs139192433) is reported in the literature a cohort of individuals affected with inherited peripheral neuropathy, although its clinical significance was considered uncertain (Antoniadi 2015). This variant is found in the non-Finnish European population with an overall allele frequency of 0.19% (247/129184 alleles, including one homozygote) in the Genome Aggregation Database. The arginine at codon 1127 is highly conserved, but computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.573). Although it population frequency is inconsistent with dominant disease, since a role in autosomal recessive disease cannot be ruled out, the clinical significance of the p.Arg1127Gln variant is uncertain at this time. References: Antoniadi et al. Application of targeted multi-gene panel testing for the diagnosis of inherited peripheral neuropathy provides a high diagnostic yield with unexpected phenotype-genotype variability. BMC Med Genet. 2015 Sep 21;16:84. -

Feb 25, 2022

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Charcot-Marie-Tooth disease type 4C

Uncertain:2

Nov 05, 2018

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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 specified

Benign:2

May 03, 2024

Athena Diagnostics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 07, 2025

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

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: SH3TC2 c.3380G>A (p.Arg1127Gln) results in a 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 allele was found at a frequency of 0.0021 in 1461892 control chromosomes, predominantly at a frequency of 0.0026 within the Non-Finnish European subpopulation in the gnomAD database, including 6 homozygotes. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database exceeds the estimated maximal expected allele frequency for a pathogenic variant in SH3TC2 causing Charcot-Marie-Tooth disease type 4C phenotype. c.3380G>A has been reported in the literature in individuals who underwent multi-gene panel testingfor Charcot-Marie-Tooth disease (e.g. Volodarsky_2021, Cortese_2020, Antoniadi_2015). These report(s) do not provide unequivocal conclusions about association of the variant with Charcot-Marie-Tooth disease type 4C. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 26392352, 31827005, 32376792). ClinVar contains an entry for this variant (Variation ID: 234414). Based on the evidence outlined above, the variant was classified as likely benign. -

Tip-toe gait

Pathogenic:1

Oct 06, 2020

Practice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice Pomarino

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

We conducted a clinical examination of patients about toe walking. The SH3TC2:c.3380G>A was detected in 3 patients. We also examined a control group of children without toe walking (100 children). In this group this variant could not be identified. Hereditary motor sensory neuropathy (HMSN), also known as Charcot-Marie-Tooth Disease (CMT), is the most commonly inherited peripheral polyneuropathy. It constitutes a group of inherited, progressive, motor and sensory peripheral nerve disorders with properties of demyelination, axonal degeneration, or both. It is classified by clinical characteristics, modes of inheritance, electrophysiologic features, metabolic defects, and specific gene markers. Our patients all walk on tiptoe, so they show similar symptoms. When we genetically test them with our toe walking panel, we find that around 90 per cent of them have a genetic variant that explains their toe walking. These can be assigned, for example, to the area of myopathies (such as variants of the COL6A3 gene), the area of hereditary neuropathies (such as variants of the KMT2C gene) or the area of metabolic diseases (such as variants of the PYGM gene). In a smaller group of patients with almost identical symptoms, no abnormality is found in the genes of our panel, but spastic paraplegia can be detected. In another small group of our toe walkers, no abnormalities can be detected in the genes analysed in our toe walking panel, nor do they suffer from spastic paraplegia, as is also the case with healthy children. In contrast to these, however, they show a tiptoe gait. These patients suffer from infantile cerebral palsy, in which toe walking can also be observed. -

Charcot-Marie-Tooth disease

Uncertain:1

Molecular Genetics Laboratory, London Health Sciences Centre

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Inborn genetic diseases

Uncertain:1

Dec 20, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R1127Q variant (also known as c.3380G>A), located in coding exon 15 of the SH3TC2 gene, results from a G to A substitution at nucleotide position 3380. The arginine at codon 1127 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is highly 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. -

SH3TC2-related disorder

Uncertain:1

Sep 28, 2023

PreventionGenetics, part of Exact Sciences

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The SH3TC2 c.3380G>A variant is predicted to result in the amino acid substitution p.Arg1127Gln. This variant has been reported with uncertain significance in a cohort study of individuals with Charcot-Marie-Tooth disease (Volodarsky et al. 2021. PubMed ID: 32376792). This variant is reported in 0.19% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/5-148388512-C-T). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Tip-toe gait;C0454644:Delayed speech and language development;C0728829:Pes cavus;na:limited range of motion of the upper ankle

Uncertain:1

Oct 06, 2020

Practice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice Pomarino

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Onset at age of three, younger halfsister also has toe walking, parents clinically not affected -

Susceptibility to mononeuropathy of the median nerve, mild

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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 and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Charcot-Marie-Tooth disease type 4

Benign:1

Jan 20, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.16

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Uncertain

0.010

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.49

T;.

Eigen

Pathogenic

0.75

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

D;D

M_CAP

Uncertain

0.091

MetaRNN

Benign

0.16

T;T

MetaSVM

Uncertain

0.22

MutationAssessor

Uncertain

2.9

M;.

PhyloP100

7.5

PrimateAI

Uncertain

0.52

PROVEAN

Uncertain

-3.6

D;D

REVEL

Uncertain

0.57

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

D;.

Vest4

0.65

MVP

0.92

MPC

0.30

ClinPred

0.12

GERP RS

5.2

Varity_R

0.81

gMVP

0.60

Mutation Taster

=94/6

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over