chr18-2673329-G-A

Position:

chr18-2673329-G-A

Variant summary

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

The NM_015295.3(SMCHD1):c.473G>A(p.Arg158His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000136 in 1,582,948 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00015 ( 0 hom. )

Consequence

SMCHD1
NM_015295.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 1.35

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 in gene, where missense usually causes diseases (based on misZ statistic), SMCHD1. . Gene score misZ 3.6318 (greater than the threshold 3.09). Trascript score misZ 3.965 (greater than threshold 3.09). GenCC has associacion of gene with facioscapulohumeral muscular dystrophy, arhinia, choanal atresia, and microphthalmia, hyposmia-nasal and ocular hypoplasia-hypogonadotropic hypogonadism syndrome.

BP4

Computational evidence support a benign effect (MetaRNN=0.20906949).

BS1

Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.0000394 (6/152098) while in subpopulation EAS AF= 0.000193 (1/5190). AF 95% confidence interval is 0.0000285. There are 0 homozygotes in gnomad4. There are 2 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAd4 at 6 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMCHD1	NM_015295.3 linkuse as main transcript	c.473G>A	p.Arg158His	missense_variant	4/48	ENST00000320876.11	NP_056110.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMCHD1	ENST00000320876.11 linkuse as main transcript	c.473G>A	p.Arg158His	missense_variant	4/48	5	NM_015295.3	ENSP00000326603	P2	A6NHR9-1
SMCHD1	ENST00000688342.1 linkuse as main transcript	c.473G>A	p.Arg158His	missense_variant	4/47			ENSP00000508422	A2
SMCHD1	ENST00000684915.1 linkuse as main transcript	n.630G>A		non_coding_transcript_exon_variant	4/14

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152098

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000329

AC:

AN:

243120

Hom.:

AF XY:

0.0000378

AC XY:

AN XY:

132176

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000572

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000630

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000147

AC:

210

AN:

1430850

Hom.:

Cov.:

AF XY:

0.000156

AC XY:

111

AN XY:

710584

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000513

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000185

Gnomad4 OTH exome

AF:

0.000102

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152098

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74290

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000762

Hom.:

Bravo

AF:

0.0000340

ExAC

AF:

0.0000166

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jan 18, 2017

- -

Facioscapulohumeral muscular dystrophy 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 13, 2023

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 158 of the SMCHD1 protein (p.Arg158His). This variant is present in population databases (rs531460906, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with SMCHD1-related conditions. ClinVar contains an entry for this variant (Variation ID: 290028). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SMCHD1 protein function with a negative predictive value of 80%. 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. -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 26, 2022

The c.473G>A (p.R158H) alteration is located in exon 4 (coding exon 4) of the SMCHD1 gene. This alteration results from a G to A substitution at nucleotide position 473, causing the arginine (R) at amino acid position 158 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Aug 29, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.081

BayesDel_addAF

Benign

-0.0083

BayesDel_noAF

Uncertain

-0.070

CADD

Benign

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.23

Eigen

Uncertain

0.23

Eigen_PC

Uncertain

0.32

FATHMM_MKL

Uncertain

0.78

LIST_S2

Uncertain

0.88

M_CAP

Benign

0.079

MetaRNN

Benign

0.21

MetaSVM

Uncertain

0.27

MutationAssessor

Benign

1.3

MutationTaster

Benign

0.83

N;N

PrimateAI

Benign

0.46

PROVEAN

Benign

-0.90

REVEL

Benign

0.28

Sift

Benign

0.090

Sift4G

Benign

0.16

Polyphen

0.82

Vest4

0.19

MVP

0.45

MPC

0.83

ClinPred

0.12

GERP RS

5.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.077

gMVP

0.38

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