Genetic Variant SMCHD1:p.Ala58Ala (chr18-2656249-G-T) – ACMG Classification: Benign (-13 pts)

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_StrongBP7BS1BS2

The NM_015295.3(SMCHD1):c.174G>T(p.Ala58Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000255 in 1,492,990 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Synonymous variant affecting the same amino acid position (i.e. A58A) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000026 ( 0 hom. )

Consequence

SMCHD1
NM_015295.3 synonymous

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: -0.813

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 Benign. Variant got -13 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.77).

BP7

Synonymous conserved (PhyloP=-0.813 with no splicing effect.

BS1

Variant frequency is greater than expected in population sas. gnomad4_exome allele frequency = 0.0000261 (35/1340890) while in subpopulation SAS AF= 0.000415 (29/69836). AF 95% confidence interval is 0.000296. There are 0 homozygotes in gnomad4_exome. There are 29 alleles in male gnomad4_exome subpopulation. Median coverage is 46. This position pass quality control queck.

BS2

High AC in GnomAdExome4 at 35 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMCHD1	NM_015295.3 link	c.174G>T	p.Ala58Ala	synonymous_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.174G>T	p.Ala58Ala	synonymous_variant	Exon 1 of 48	5	NM_015295.3	ENSP00000326603.7	A6NHR9-1
SMCHD1	ENST00000688342.1 link	c.174G>T	p.Ala58Ala	synonymous_variant	Exon 1 of 47			ENSP00000508422.1	A0A8I5KRS9
SMCHD1	ENST00000684915.1 link	n.331G>T		non_coding_transcript_exon_variant	Exon 1 of 14

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152100

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000474

AC:

AN:

147528

Hom.:

AF XY:

0.0000479

AC XY:

AN XY:

83462

show subpopulations

Gnomad AFR exome

AF:

0.000117

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000282

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000128

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000261

AC:

AN:

1340890

Hom.:

Cov.:

AF XY:

0.0000437

AC XY:

AN XY:

664058

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:

0.000415

Gnomad4 FIN exome

AF:

0.0000213

Gnomad4 NFE exome

AF:

0.00000470

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152100

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74284

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Facioscapulohumeral muscular dystrophy 2

Benign:1

Sep 23, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.77

CADD

Benign

6.1

DANN

Benign

0.46

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