18-2656110-C-A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_015295.3(SMCHD1):​c.35C>A​(p.Ala12Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000417 in 1,440,168 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A12T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000031 ( 0 hom. )

Consequence

SMCHD1
NM_015295.3 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.838

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: Likely_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.037575424).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMCHD1NM_015295.3 linkc.35C>A p.Ala12Asp missense_variant Exon 1 of 48 ENST00000320876.11 NP_056110.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SMCHD1ENST00000320876.11 linkc.35C>A p.Ala12Asp missense_variant Exon 1 of 48 5 NM_015295.3 ENSP00000326603.7 A6NHR9-1
SMCHD1ENST00000688342.1 linkc.35C>A p.Ala12Asp missense_variant Exon 1 of 47 ENSP00000508422.1 A0A8I5KRS9
SMCHD1ENST00000684915.1 linkn.192C>A non_coding_transcript_exon_variant Exon 1 of 14
ENSG00000293256ENST00000733457.1 linkn.-240G>T upstream_gene_variant

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152142
Hom.:
0
Cov.:
33
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:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000897
AC:
1
AN:
111500
AF XY:
0.00
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000172
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000311
AC:
4
AN:
1288026
Hom.:
0
Cov.:
29
AF XY:
0.00000158
AC XY:
1
AN XY:
633250
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
25776
American (AMR)
AF:
0.00
AC:
0
AN:
17856
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19288
East Asian (EAS)
AF:
0.00
AC:
0
AN:
30600
South Asian (SAS)
AF:
0.00
AC:
0
AN:
61868
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
47074
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5020
European-Non Finnish (NFE)
AF:
0.00000389
AC:
4
AN:
1028298
Other (OTH)
AF:
0.00
AC:
0
AN:
52246
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.513
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000131
AC:
2
AN:
152142
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74344
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41414
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68006
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000227

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Facioscapulohumeral muscular dystrophy 2 Uncertain:1
Jun 13, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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: "Tolerated"; 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. This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 12 of the SMCHD1 protein (p.Ala12Asp). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.091
BayesDel_addAF
Benign
-0.24
T
BayesDel_noAF
Benign
-0.59
CADD
Benign
18
DANN
Benign
0.78
DEOGEN2
Benign
0.050
T
Eigen
Benign
-0.66
Eigen_PC
Benign
-0.56
FATHMM_MKL
Benign
0.075
N
LIST_S2
Benign
0.44
T
M_CAP
Benign
0.052
D
MetaRNN
Benign
0.038
T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.0
N
PhyloP100
0.84
PrimateAI
Uncertain
0.68
T
PROVEAN
Benign
-0.12
N
REVEL
Benign
0.044
Sift
Benign
0.27
T
Sift4G
Benign
0.56
T
Polyphen
0.010
B
Vest4
0.11
MutPred
0.23
Loss of sheet (P = 0.0315);
MVP
0.043
MPC
0.98
ClinPred
0.049
T
GERP RS
2.2
PromoterAI
-0.16
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.2
Varity_R
0.089
gMVP
0.30
Mutation Taster
=93/7
polymorphism

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

Other links and lift over

dbSNP: rs955025983; hg19: chr18-2656109; API