chr15-66704034-T-C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_005585.5(SMAD6):​c.776T>C​(p.Val259Ala) variant causes a missense change. The variant allele was found at a frequency of 0.0000575 in 1,513,680 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V259L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000059 ( 0 hom. )

Consequence

SMAD6
NM_005585.5 missense

Scores

6
9
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3O:1

Conservation

PhyloP100: 5.61

Publications

0 publications found
Variant links:
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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.857

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005585.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SMAD6
NM_005585.5
MANE Select
c.776T>Cp.Val259Ala
missense
Exon 1 of 4NP_005576.3
SMAD6
NR_027654.2
n.1799T>C
non_coding_transcript_exon
Exon 1 of 5

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SMAD6
ENST00000288840.10
TSL:1 MANE Select
c.776T>Cp.Val259Ala
missense
Exon 1 of 4ENSP00000288840.5
SMAD6
ENST00000557916.5
TSL:1
n.776T>C
non_coding_transcript_exon
Exon 1 of 5ENSP00000452955.1
SMAD6
ENST00000612349.1
TSL:6
n.958T>C
non_coding_transcript_exon
Exon 1 of 1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152118
Hom.:
0
Cov.:
33
show subpopulations
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:
0.0000882
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000806
AC:
1
AN:
124018
AF XY:
0.00
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000186
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000595
AC:
81
AN:
1361562
Hom.:
0
Cov.:
32
AF XY:
0.0000489
AC XY:
33
AN XY:
675262
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
28134
American (AMR)
AF:
0.00
AC:
0
AN:
34518
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24104
East Asian (EAS)
AF:
0.00
AC:
0
AN:
30666
South Asian (SAS)
AF:
0.00
AC:
0
AN:
77258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
33996
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4130
European-Non Finnish (NFE)
AF:
0.0000737
AC:
79
AN:
1072498
Other (OTH)
AF:
0.0000356
AC:
2
AN:
56258
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
Heterozygous variant carriers
0
4
9
13
18
22
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000394
AC:
6
AN:
152118
Hom.:
0
Cov.:
33
AF XY:
0.0000538
AC XY:
4
AN XY:
74306
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41460
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5158
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000882
AC:
6
AN:
67998
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.533
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000712
Hom.:
0
Bravo
AF:
0.0000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Jul 30, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Inborn genetic diseases Uncertain:1
Jul 26, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.776T>C (p.V259A) alteration is located in exon 1 (coding exon 1) of the SMAD6 gene. This alteration results from a T to C substitution at nucleotide position 776, causing the valine (V) at amino acid position 259 to be replaced by an alanine (A). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Aortic valve disease 2 Uncertain:1
Jan 15, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 259 of the SMAD6 protein (p.Val259Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SMAD6-related conditions. ClinVar contains an entry for this variant (Variation ID: 579137). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt SMAD6 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Aortic valve disease 2;C4479496:Craniosynostosis 7 Other:1
GenomeConnect - Invitae Patient Insights Network
Significance:not provided
Review Status:no classification provided
Collection Method:phenotyping only

Variant interpreted as Uncertain significance and reported on 09-25-2020 by Invitae. GenomeConnect-Invitae Patient Insights Network assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. Phenotypic details are available under supporting information.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.27
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Uncertain
0.030
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.94
D
Eigen
Uncertain
0.56
Eigen_PC
Uncertain
0.51
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Benign
0.81
T
M_CAP
Uncertain
0.18
D
MetaRNN
Pathogenic
0.86
D
MetaSVM
Uncertain
0.28
D
MutationAssessor
Pathogenic
2.9
M
PhyloP100
5.6
PrimateAI
Pathogenic
0.93
D
PROVEAN
Uncertain
-2.6
D
REVEL
Pathogenic
0.76
Sift
Benign
0.045
D
Sift4G
Uncertain
0.018
D
Polyphen
0.92
P
Vest4
0.76
MutPred
0.66
Gain of disorder (P = 0.0348)
MVP
0.85
MPC
0.89
ClinPred
0.97
D
GERP RS
4.1
Varity_R
0.25
gMVP
0.63
Mutation Taster
=45/55
disease causing

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

Publications

Other links and lift over

dbSNP: rs1049275389; hg19: chr15-66996372; API