15-66703276-C-T

Variant names:

• chr15-66703276-C-T
• rs1893016037
• NM_005585.5:c.18C>T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_005585.5(SMAD6):​c.18C>T​(p.Arg6Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000135 in 1,484,944 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. R6R) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 7.5e-7 (0 hom.)
• Consequence: SMAD6 NM_005585.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.34
• Publications: 0 publications found

Genes affected

SMAD6 (HGNC:6772): (SMAD family member 6) The protein encoded by this gene belongs to the SMAD family of proteins, which are related to Drosophila 'mothers against decapentaplegic' (Mad) and C. elegans Sma. SMAD proteins are signal transducers and transcriptional modulators that mediate multiple signaling pathways. This protein functions in the negative regulation of BMP and TGF-beta/activin-signalling. Multiple transcript variants have been found for this gene.[provided by RefSeq, Sep 2014]

SMAD6 Gene-Disease associations (from GenCC):

• craniosynostosis 7

  Inheritance: AD, Unknown Classification: STRONG, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
• radioulnar synostosis, nonsyndromic, susceptibility to

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics
• aortic valve disease 2

  Inheritance: AD, Unknown Classification: MODERATE, LIMITED Submitted by: Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• familial bicuspid aortic valve

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• congenital radioulnar synostosis

  Inheritance: AR, Unknown Classification: SUPPORTIVE, LIMITED Submitted by: Ambry Genetics, Orphanet
• congenital heart defects, multiple types

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.45).
• BP7: Synonymous conserved (PhyloP=2.34 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMAD6	NM_005585.5	c.18C>T	p.Arg6Arg	synonymous_variant	Exon 1 of 4	ENST00000288840.10	NP_005576.3
SMAD6	NR_027654.2	n.1041C>T		non_coding_transcript_exon_variant	Exon 1 of 5
SMAD6	XR_931827.3	n.1041C>T		non_coding_transcript_exon_variant	Exon 1 of 4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMAD6	ENST00000288840.10	c.18C>T	p.Arg6Arg	synonymous_variant	Exon 1 of 4	1	NM_005585.5	ENSP00000288840.5
SMAD6	ENST00000557916.5	n.18C>T		non_coding_transcript_exon_variant	Exon 1 of 5	1		ENSP00000452955.1
SMAD6	ENST00000612349.1	n.200C>T		non_coding_transcript_exon_variant	Exon 1 of 1	6

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152076 Hom.: 0 Cov.: 33

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: 0.0000945

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 7.50e-7 AC: 1 AN: 1332868 Hom.: 0 Cov.: 31 AF XY: 0.00000152 AC XY: 1 AN XY: 658442

African (AFR) AF: 0.00 AC: 0 AN: 26770

American (AMR) AF: 0.00 AC: 0 AN: 26194

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 23164

East Asian (EAS) AF: 0.00 AC: 0 AN: 29020

South Asian (SAS) AF: 0.00 AC: 0 AN: 72538

European-Finnish (FIN) AF: 0.0000211 AC: 1 AN: 47336

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4196

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1049256

Other (OTH) AF: 0.00 AC: 0 AN: 54394

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152076 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74302

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41428

American (AMR) AF: 0.00 AC: 0 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.0000945 AC: 1 AN: 10582

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67984

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

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.45
CADD	Benign	14
DANN	Uncertain	0.98
PhyloP100		2.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1893016037; hg19: chr15-66995614;