NM_017777.4:c.763G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_017777.4(MKS1):​c.763G>A​(p.Gly255Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000682 in 1,614,066 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G255W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

MKS1
NM_017777.4 missense

Scores

1
15
3

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.97

Publications

5 publications found
Variant links:
Genes affected
MKS1 (HGNC:7121): (MKS transition zone complex subunit 1) The protein encoded by this gene localizes to the basal body and is required for formation of the primary cilium in ciliated epithelial cells. Mutations in this gene result in Meckel syndrome type 1 and in Bardet-Biedl syndrome type 13. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2009]
MKS1 Gene-Disease associations (from GenCC):
  • Meckel syndrome, type 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Myriad Women’s Health, Labcorp Genetics (formerly Invitae)
  • Bardet-Biedl syndrome 13
    Inheritance: Unknown, AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P
  • Joubert syndrome 28
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • Bardet-Biedl syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Joubert syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Joubert syndrome with ocular defect
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Meckel syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MKS1NM_017777.4 linkc.763G>A p.Gly255Arg missense_variant Exon 8 of 18 ENST00000393119.7 NP_060247.2 Q9NXB0-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MKS1ENST00000393119.7 linkc.763G>A p.Gly255Arg missense_variant Exon 8 of 18 1 NM_017777.4 ENSP00000376827.2 Q9NXB0-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152190
Hom.:
0
Cov.:
32
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000401
AC:
1
AN:
249580
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000684
AC:
10
AN:
1461876
Hom.:
0
Cov.:
33
AF XY:
0.00000550
AC XY:
4
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000719
AC:
8
AN:
1111998
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.440
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152190
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74352
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41426
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000827
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Feb 23, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MKS1 c.763G>A (p.Gly255Arg) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 249580 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.763G>A in individuals affected with Meckel Syndrome Type 1 and no experimental evidence demonstrating its impact on protein function have been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.36
BayesDel_addAF
Uncertain
0.050
T
BayesDel_noAF
Uncertain
-0.070
CADD
Benign
21
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.83
D;T;.
Eigen
Benign
0.13
Eigen_PC
Benign
0.13
FATHMM_MKL
Uncertain
0.97
D
LIST_S2
Uncertain
0.89
D;D;D
M_CAP
Uncertain
0.18
D
MetaRNN
Uncertain
0.64
D;D;D
MetaSVM
Uncertain
0.016
D
MutationAssessor
Uncertain
2.5
M;.;.
PhyloP100
4.0
PrimateAI
Uncertain
0.62
T
PROVEAN
Uncertain
-2.9
D;.;D
REVEL
Uncertain
0.39
Sift
Uncertain
0.011
D;.;D
Sift4G
Uncertain
0.0070
D;D;D
Polyphen
0.56
P;.;.
Vest4
0.55
MutPred
0.36
Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);.;
MVP
0.74
MPC
0.32
ClinPred
0.94
D
GERP RS
4.9
Varity_R
0.27
gMVP
0.84
Mutation Taster
=94/6
polymorphism

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

Other links and lift over

dbSNP: rs201237547; hg19: chr17-56290438; COSMIC: COSV58302832; COSMIC: COSV58302832; API