rs191487554

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBS1_SupportingBS2

The NM_015295.3(SMCHD1):​c.4255A>G​(p.Thr1419Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000604 in 1,573,618 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00028 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

SMCHD1
NM_015295.3 missense

Scores

19

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 1.61

Publications

0 publications found
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 Gene-Disease associations (from GenCC):
  • arhinia, choanal atresia, and microphthalmia
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, G2P, Ambry Genetics, ClinGen, Illumina
  • facioscapulohumeral muscular dystrophy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • hyposmia-nasal and ocular hypoplasia-hypogonadotropic hypogonadism syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -9 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.013257593).
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000276 (42/152238) while in subpopulation AFR AF = 0.000914 (38/41568). AF 95% confidence interval is 0.000684. There are 0 homozygotes in GnomAd4. There are 17 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 AC in GnomAd4 at 42 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMCHD1NM_015295.3 linkc.4255A>G p.Thr1419Ala missense_variant Exon 33 of 48 ENST00000320876.11 NP_056110.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SMCHD1ENST00000320876.11 linkc.4255A>G p.Thr1419Ala missense_variant Exon 33 of 48 5 NM_015295.3 ENSP00000326603.7 A6NHR9-1

Frequencies

GnomAD3 genomes
AF:
0.000276
AC:
42
AN:
152120
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000917
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.00144
GnomAD2 exomes
AF:
0.0000482
AC:
10
AN:
207588
AF XY:
0.0000438
show subpopulations
Gnomad AFR exome
AF:
0.000567
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000738
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000208
GnomAD4 exome
AF:
0.0000373
AC:
53
AN:
1421380
Hom.:
0
Cov.:
29
AF XY:
0.0000255
AC XY:
18
AN XY:
707072
show subpopulations
African (AFR)
AF:
0.00146
AC:
44
AN:
30078
American (AMR)
AF:
0.00
AC:
0
AN:
34866
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
36254
South Asian (SAS)
AF:
0.0000126
AC:
1
AN:
79656
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53092
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5676
European-Non Finnish (NFE)
AF:
0.00000182
AC:
2
AN:
1097962
Other (OTH)
AF:
0.000102
AC:
6
AN:
58662
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.453
Heterozygous variant carriers
0
3
5
8
10
13
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000276
AC:
42
AN:
152238
Hom.:
0
Cov.:
32
AF XY:
0.000228
AC XY:
17
AN XY:
74422
show subpopulations
African (AFR)
AF:
0.000914
AC:
38
AN:
41568
American (AMR)
AF:
0.0000654
AC:
1
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67956
Other (OTH)
AF:
0.00142
AC:
3
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.476
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000717
Hom.:
0
Bravo
AF:
0.000204
ESP6500AA
AF:
0.000274
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000579
AC:
7
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Oct 10, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 01, 2019
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Facioscapulohumeral muscular dystrophy 2 Uncertain:1
Aug 05, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 1419 of the SMCHD1 protein (p.Thr1419Ala). This variant is present in population databases (rs191487554, gnomAD 0.07%), and has an allele count higher than expected for a pathogenic variant. 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: 532802). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.056
BayesDel_addAF
Benign
-0.60
T
BayesDel_noAF
Benign
-0.70
CADD
Benign
12
DANN
Benign
0.59
DEOGEN2
Benign
0.050
T
Eigen
Benign
-0.92
Eigen_PC
Benign
-0.81
FATHMM_MKL
Benign
0.12
N
LIST_S2
Benign
0.52
T
M_CAP
Benign
0.0064
T
MetaRNN
Benign
0.013
T
MetaSVM
Benign
-0.99
T
MutationAssessor
Benign
0.0
N
PhyloP100
1.6
PrimateAI
Benign
0.32
T
PROVEAN
Benign
-0.31
N
REVEL
Benign
0.069
Sift
Benign
0.76
T
Sift4G
Benign
0.73
T
Polyphen
0.0
B
Vest4
0.087
MVP
0.17
MPC
0.21
ClinPred
0.020
T
GERP RS
3.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.026
gMVP
0.13
Mutation Taster
=89/11
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs191487554; hg19: chr18-2751365; API