18-2750450-C-T

Position:

chr18-2750450-C-T

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 1P and 11B. PP2BP4_ModerateBP6BS1BS2

The NM_015295.3(SMCHD1):c.4108C>T(p.Arg1370Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000745 in 1,610,852 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

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

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

SMCHD1
NM_015295.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 0.580

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:

SMCHD1 (HGNC:):

SMCHD1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -10 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=0.1503129).

BP6

Variant 18-2750450-C-T is Benign according to our data. Variant chr18-2750450-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 448425.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.

BS1

Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.0000395 (6/152058) while in subpopulation AMR AF= 0.000197 (3/15252). AF 95% confidence interval is 0.000053. There are 0 homozygotes in gnomad4. There are 2 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

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.4108C>T	p.Arg1370Cys	missense_variant	32/48	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.4108C>T	p.Arg1370Cys	missense_variant	32/48	5	NM_015295.3	ENSP00000326603.7		A6NHR9-1

Frequencies

GnomAD3 genomes

AF:

0.0000395

AC:

AN:

152058

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000197

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000409

AC:

AN:

244284

Hom.:

AF XY:

0.00000754

AC XY:

AN XY:

132566

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000331

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000411

AC:

AN:

1458794

Hom.:

Cov.:

AF XY:

0.00000414

AC XY:

AN XY:

725514

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000233

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000395

AC:

AN:

152058

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74250

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000197

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000302

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Facioscapulohumeral muscular dystrophy 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 27, 2023

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 1370 of the SMCHD1 protein (p.Arg1370Cys). 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. 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: 448425). 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. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Jul 22, 2020

- -

not specified

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Athena Diagnostics

Apr 21, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.066

BayesDel_addAF

Benign

-0.13

BayesDel_noAF

Benign

-0.42

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.52

Eigen

Benign

-0.050

Eigen_PC

Benign

0.097

FATHMM_MKL

Benign

0.68

LIST_S2

Benign

0.86

M_CAP

Benign

0.012

MetaRNN

Benign

0.15

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.8

PrimateAI

Benign

0.33

PROVEAN

Benign

-2.2

REVEL

Benign

0.12

Sift

Benign

0.087

Sift4G

Benign

0.11

Polyphen

0.086

Vest4

0.15

MutPred

0.52

Gain of catalytic residue at L1371 (P = 0.0077);

MVP

0.14

MPC

0.29

ClinPred

0.34

GERP RS

5.0

Varity_R

0.11

gMVP

0.58

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