18-2656118-G-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 1P and 7B. PP2BP4_ModerateBS1_SupportingBS2

The NM_015295.3(SMCHD1):c.43G>T(p.Gly15Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,463,788 control chromosomes in the GnomAD database, including 1 homozygotes. 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 Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. G15G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00024 ( 1 hom., cov: 33)

Exomes 𝑓: 0.0000015 ( 0 hom. )

Consequence

SMCHD1
NM_015295.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.94

Variant links:

Genes affected

SMCHD1 (HGNC:29090): (structural maintenance of chromosomes flexible hinge domain containing 1) This gene encodes a protein which contains a hinge region domain found in members of the SMC (structural maintenance of chromosomes) protein family. [provided by RefSeq, Dec 2011]

SMCHD1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

PP2

Missense variant where missense usually causes diseases, SMCHD1

BP4

Computational evidence support a benign effect (MetaRNN=0.12141144).

BS1

Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.000237 (36/152142) while in subpopulation AMR AF= 0.00235 (36/15290). AF 95% confidence interval is 0.00175. There are 1 homozygotes in gnomad4. There are 23 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAd at 36 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMCHD1	NM_015295.3 linkuse as main transcript	c.43G>T	p.Gly15Trp	missense_variant	1/48	ENST00000320876.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMCHD1	ENST00000320876.11 linkuse as main transcript	c.43G>T	p.Gly15Trp	missense_variant	1/48	5	NM_015295.3	P2	A6NHR9-1
SMCHD1	ENST00000688342.1 linkuse as main transcript	c.43G>T	p.Gly15Trp	missense_variant	1/47			A2
SMCHD1	ENST00000684915.1 linkuse as main transcript	n.200G>T		non_coding_transcript_exon_variant	1/14

Frequencies

GnomAD3 genomes

AF:

0.000237

AC:

AN:

152142

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00235

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000152

AC:

AN:

131876

Hom.:

AF XY:

0.0000135

AC XY:

AN XY:

74110

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000866

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000655

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000152

AC:

AN:

1311646

Hom.:

Cov.:

AF XY:

0.00000155

AC XY:

AN XY:

647080

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000982

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.000237

AC:

AN:

152142

Hom.:

Cov.:

AF XY:

0.000309

AC XY:

AN XY:

74322

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00235

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.000121

ExAC

AF:

0.0000250

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Facioscapulohumeral muscular dystrophy 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 17, 2022

This sequence change replaces glycine, which is neutral and non-polar, with tryptophan, which is neutral and slightly polar, at codon 15 of the SMCHD1 protein (p.Gly15Trp). 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with SMCHD1-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.19

BayesDel_addAF

Benign

-0.13

BayesDel_noAF

Benign

-0.42

Cadd

Benign

Dann

Benign

0.84

DEOGEN2

Benign

0.088

Eigen

Benign

-0.18

Eigen_PC

Benign

-0.19

FATHMM_MKL

Benign

0.34

LIST_S2

Benign

0.49

M_CAP

Pathogenic

0.42

MetaRNN

Benign

0.12

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.7

MutationTaster

Benign

1.0

N;N

PrimateAI

Uncertain

0.78

PROVEAN

Benign

-0.80

REVEL

Benign

0.086

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0050

Polyphen

0.66

Vest4

0.33

MutPred

0.35

Gain of sheet (P = 0.0149);

MVP

0.043

MPC

0.77

ClinPred

0.76

GERP RS

3.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.2

Varity_R

0.16

gMVP

0.22

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over