Genetic Variant SMCHD1:p.Ala12Val (chr18-2656110-C-T) – ACMG Classification: Likely_benign (-1 pts)

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2PP2BP4_Strong

The NM_015295.3(SMCHD1):c.35C>T(p.Ala12Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000311 in 1,288,028 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000031 ( 0 hom. )

Consequence

SMCHD1
NM_015295.3 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.838

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:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant in the SMCHD1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 23 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: 3.6318 (above the threshold of 3.09). Trascript score misZ: 3.965 (above the threshold of 3.09). GenCC associations: The gene is linked to facioscapulohumeral muscular dystrophy, arhinia, choanal atresia, and microphthalmia, hyposmia-nasal and ocular hypoplasia-hypogonadotropic hypogonadism syndrome.

BP4

Computational evidence support a benign effect (MetaRNN=0.028318286).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMCHD1	NM_015295.3 link	c.35C>T	p.Ala12Val	missense_variant	Exon 1 of 48	ENST00000320876.11	NP_056110.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SMCHD1	ENST00000320876.11 link	c.35C>T	p.Ala12Val	missense_variant	Exon 1 of 48	5	NM_015295.3	ENSP00000326603.7	A6NHR9-1
SMCHD1	ENST00000688342.1 link	c.35C>T	p.Ala12Val	missense_variant	Exon 1 of 47			ENSP00000508422.1	A0A8I5KRS9
SMCHD1	ENST00000684915.1 link	n.192C>T		non_coding_transcript_exon_variant	Exon 1 of 14

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000897

AC:

AN:

111500

Hom.:

AF XY:

0.0000161

AC XY:

AN XY:

62292

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:

0.0000856

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000311

AC:

AN:

1288028

Hom.:

Cov.:

AF XY:

0.00000474

AC XY:

AN XY:

633250

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:

0.0000485

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.72e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.088

BayesDel_addAF

Benign

-0.28

BayesDel_noAF

Benign

-0.64

CADD

Benign

DANN

Benign

0.95

DEOGEN2

Benign

0.050

Eigen

Benign

-0.71

Eigen_PC

Benign

-0.61

FATHMM_MKL

Benign

0.027

LIST_S2

Benign

0.54

M_CAP

Benign

0.037

MetaRNN

Benign

0.028

MetaSVM

Benign

-0.98

MutationAssessor

Benign

0.0

PrimateAI

Uncertain

0.66

PROVEAN

Benign

-0.23

REVEL

Benign

0.021

Sift

Benign

0.68

Sift4G

Benign

0.54

Polyphen

0.0020

Vest4

0.073

MutPred

0.24

Gain of sheet (P = 0.0221);

MVP

0.068

MPC

0.65

ClinPred

0.058

GERP RS

2.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.2

Varity_R

0.027

gMVP

0.17

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

Computational scores

Splicing

Publications

LitVar

Other links and lift over