Genetic Variant SMCHD1:p.Ala58Ala (chr18-2656249-G-T) – ACMG Classification: Benign (-15 pts)

Variant summary

Our verdict is Benign. The variant received -15 ACMG points: 0P and 15B. BP4_StrongBP6_ModerateBP7BS1BS2

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

Publications

17 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

SMCHD1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -15 ACMG points.

BP4

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

BP6

Variant 18-2656249-G-T is Benign according to our data. Variant chr18-2656249-G-T is described in ClinVar as Likely_benign. ClinVar VariationId is 1913208.Status of the report is criteria_provided_single_submitter, 1 stars.

BP7

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

BS1

Variant frequency is greater than expected in population sas. GnomAdExome4 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 GnomAdExome4. There are 29 alleles in the male GnomAdExome4 subpopulation. Median coverage is 46. This position passed quality control check.

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
SMCHD1	ENST00000320876.11 link	c.174G>T	p.Ala58Ala	synonymous_variant	Exon 1 of 48	5	NM_015295.3	ENSP00000326603.7
SMCHD1	ENST00000688342.1 link	c.174G>T	p.Ala58Ala	synonymous_variant	Exon 1 of 47			ENSP00000508422.1
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

GnomAD2 exomes

AF:

0.0000474

AC:

AN:

147528

AF XY:

0.0000479

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 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

African (AFR)

AF:

0.00

AC:

AN:

26190

American (AMR)

AF:

0.00

AC:

AN:

20522

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

22324

East Asian (EAS)

AF:

0.00

AC:

AN:

31706

South Asian (SAS)

AF:

0.000415

AC:

AN:

69836

European-Finnish (FIN)

AF:

0.0000213

AC:

AN:

46960

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5370

European-Non Finnish (NFE)

AF:

0.00000470

AC:

AN:

1062860

Other (OTH)

AF:

0.00

AC:

AN:

55122

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.522

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000197

AC:

AN:

152100

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74284

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41426

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5184

South Asian (SAS)

AF:

0.000207

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10592

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67998

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.00

Hom.:

1129

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

(source)

DANN

Benign

0.46

PhyloP100

-0.81

Mutation Taster

=100/0

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over