4-3492937-ACCC-ACCCC

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_173660.5(DOK7):​c.957dup​(p.Lys320GlnfsTer49) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000142 in 1,543,892 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

DOK7
NM_173660.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 1.60
Variant links:
Genes affected
DOK7 (HGNC:26594): (docking protein 7) The protein encoded by this gene is essential for neuromuscular synaptogenesis. The protein functions in aneural activation of muscle-specific receptor kinase, which is required for postsynaptic differentiation, and in the subsequent clustering of the acetylcholine receptor in myotubes. This protein can also induce autophosphorylation of muscle-specific receptor kinase. Mutations in this gene are a cause of familial limb-girdle myasthenia autosomal recessive, which is also known as congenital myasthenic syndrome type 1B. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2009]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 48 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 4-3492937-A-AC is Pathogenic according to our data. Variant chr4-3492937-A-AC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 465693.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
DOK7NM_173660.5 linkuse as main transcriptc.957dup p.Lys320GlnfsTer49 frameshift_variant 7/7 ENST00000340083.6

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
DOK7ENST00000340083.6 linkuse as main transcriptc.957dup p.Lys320GlnfsTer49 frameshift_variant 7/71 NM_173660.5 P1Q18PE1-1

Frequencies

GnomAD3 genomes
AF:
0.0000198
AC:
3
AN:
151486
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.0000727
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
GnomAD3 exomes
AF:
0.0000290
AC:
4
AN:
138024
Hom.:
0
AF XY:
0.0000399
AC XY:
3
AN XY:
75260
show subpopulations
Gnomad AFR exome
AF:
0.000145
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000934
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000379
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000136
AC:
19
AN:
1392406
Hom.:
0
Cov.:
110
AF XY:
0.0000116
AC XY:
8
AN XY:
687358
show subpopulations
Gnomad4 AFR exome
AF:
0.0000316
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000280
Gnomad4 SAS exome
AF:
0.0000126
Gnomad4 FIN exome
AF:
0.0000745
Gnomad4 NFE exome
AF:
0.0000120
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000198
AC:
3
AN:
151486
Hom.:
0
Cov.:
34
AF XY:
0.0000271
AC XY:
2
AN XY:
73896
show subpopulations
Gnomad4 AFR
AF:
0.0000727
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Fetal akinesia deformation sequence 1;C1850792:Congenital myasthenic syndrome 10 Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingInvitaeDec 03, 2016This sequence change inserts 1 nucleotide in exon 7 of the DOK7 mRNA (c.957dupC), causing a frameshift at codon 320. This creates a premature translational stop signal in the last exon of the DOK7 mRNA (p.Lys320Glnfs*49). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 185 amino acids of the DOK7 protein. While this particular variant has not been reported in the literature, truncating variants in DOK7 are known to be pathogenic (PMID: 16917026) A different truncation downstream of this variant (p.1124_1127dupTGCC) has been determined to be pathogenic (PMID: 16917026, 23657916). This suggests that deletion of this region of the DOK7 protein is causative of disease. In summary, this variant is a rare duplication that is expected to disrupt the last 185 amino acids of the DOK7 protein. This evidence indicates that the variant is pathogenic, but additional data is needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Fetal akinesia deformation sequence 3 Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingBaylor GeneticsJan 06, 2024- -
Fetal akinesia deformation sequence 1 Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingMendelicsMay 28, 2019- -
Congenital myasthenic syndrome Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpApr 24, 2023Variant summary: DOK7 c.957dupC (p.Lys320GlnfsX49) results in a premature termination codon, predicted to cause a truncation of the encoded protein, which are commonly known mechanisms for disease. Variants downstream of this position have been classified as pathogenic by our laboratory (e.g. c.1263dupC). The variant allele was found at a frequency of 2.9e-05 in 138024 control chromosomes. To our knowledge, no occurrence of c.957dupC in individuals affected with Congenital Myasthenic Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs794727884; hg19: chr4-3494664; API