18-2740800-A-G

Variant names:

• chr18-2740800-A-G
• rs115632137
• NM_015295.3:c.3612A>G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_015295.3(SMCHD1):​c.3612A>G​(p.Ser1204Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,160 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. S1204S) has been classified as Benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: SMCHD1 NM_015295.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0650
• Publications: 1 publications found

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

ENSG00000266049 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.5).
• BP7: Synonymous conserved (PhyloP=-0.065 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015295.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMCHD1	NM_015295.3	MANE Select	c.3612A>G	p.Ser1204Ser	synonymous	Exon 28 of 48	NP_056110.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMCHD1	ENST00000320876.11	TSL:5 MANE Select	c.3612A>G	p.Ser1204Ser	synonymous	Exon 28 of 48	ENSP00000326603.7
	SMCHD1	ENST00000688342.1		c.3612A>G	p.Ser1204Ser	synonymous	Exon 28 of 47	ENSP00000508422.1
	SMCHD1	ENST00000577880.5	TSL:2	n.2025A>G		non_coding_transcript_exon	Exon 17 of 38	ENSP00000463049.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152160 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 29

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152160 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74334

African (AFR) AF: 0.00 AC: 0 AN: 41424

American (AMR) AF: 0.00 AC: 0 AN: 15274

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68022

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00 Hom.: 4

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.50
CADD	Benign	9.8
DANN	Benign	0.79
PhyloP100		-0.065
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs115632137; hg19: chr18-2740798;