4-3493242-GC-GCC

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_173660.5(DOK7):​c.1263dupC​(p.Ser422LeufsTer97) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000123 in 1,611,824 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 34)
Exomes 𝑓: 0.00012 ( 0 hom. )

Consequence

DOK7
NM_173660.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:14

Conservation

PhyloP100: 0.0800

Publications

5 publications found
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]
DOK7 Gene-Disease associations (from GenCC):
  • congenital myasthenic syndrome 10
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
  • fetal akinesia deformation sequence 3
    Inheritance: AR Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • fetal akinesia deformation sequence 1
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • postsynaptic congenital myasthenic syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 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 36 pathogenic variants in the truncated region.
PP5
Variant 4-3493242-G-GC is Pathogenic according to our data. Variant chr4-3493242-G-GC is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 1274.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DOK7NM_173660.5 linkc.1263dupC p.Ser422LeufsTer97 frameshift_variant Exon 7 of 7 ENST00000340083.6 NP_775931.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DOK7ENST00000340083.6 linkc.1263dupC p.Ser422LeufsTer97 frameshift_variant Exon 7 of 7 1 NM_173660.5 ENSP00000344432.5
DOK7ENST00000643608.1 linkc.831dupC p.Ser278LeufsTer258 frameshift_variant Exon 5 of 8 ENSP00000495701.1
DOK7ENST00000515886.5 linkc.333dupC p.Ser112LeufsTer97 frameshift_variant Exon 4 of 4 2 ENSP00000492194.1
DOK7ENST00000507039.5 linkc.*484dupC 3_prime_UTR_variant Exon 7 of 7 2 ENSP00000423614.1

Frequencies

GnomAD3 genomes
AF:
0.000125
AC:
19
AN:
152192
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.000289
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:
0.000103
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000758
AC:
18
AN:
237478
AF XY:
0.0000920
show subpopulations
Gnomad AFR exome
AF:
0.000206
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:
0.000115
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000123
AC:
179
AN:
1459632
Hom.:
0
Cov.:
95
AF XY:
0.000116
AC XY:
84
AN XY:
726084
show subpopulations
African (AFR)
AF:
0.000269
AC:
9
AN:
33462
American (AMR)
AF:
0.00
AC:
0
AN:
44666
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26106
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39672
South Asian (SAS)
AF:
0.0000464
AC:
4
AN:
86172
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51842
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000143
AC:
159
AN:
1111634
Other (OTH)
AF:
0.000116
AC:
7
AN:
60310
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.477
Heterozygous variant carriers
0
14
27
41
54
68
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000125
AC:
19
AN:
152192
Hom.:
0
Cov.:
34
AF XY:
0.000161
AC XY:
12
AN XY:
74354
show subpopulations
African (AFR)
AF:
0.000289
AC:
12
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000103
AC:
7
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.509
Heterozygous variant carriers
0
2
4
5
7
9
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:
0.000130
Hom.:
0
Bravo
AF:
0.000132
EpiCase
AF:
0.000109
EpiControl
AF:
0.000178

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:14
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Fetal akinesia deformation sequence 3 Pathogenic:3
Jun 01, 2022
Solve-RD Consortium
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:provider interpretation

Variant confirmed as disease-causing by referring clinical team -

Sep 29, 2006
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Mar 27, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:3
Jan 11, 2024
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 13, 2024
Mayo Clinic Laboratories, Mayo Clinic
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PM2_moderate, PM3_very_strong, PS4 -

Mar 07, 2024
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Identified with a second DOK7 variant without confirmation of phase in patients with congenital myasthenic syndromes (PMID: 16917026, 37273706, 22661499, 18626973); Frameshift variant predicted to result in protein truncation, as the last 83 amino acids are replaced with 96 different amino acids, and other loss-of-function variants have been reported downstream in HGMD; This variant is associated with the following publications: (PMID: 31589614, 21850686, 18161030, 32153140, 31880392, 33726816, 16917026, 37273706, 22661499, 18626973) -

Congenital myasthenic syndrome 10 Pathogenic:2
Jun 11, 2019
Institute of Human Genetics Munich, TUM University Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 29, 2006
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Rett syndrome Pathogenic:1
-
Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Congenital myasthenic syndrome 10;C4760599:Fetal akinesia deformation sequence 3 Pathogenic:1
May 31, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Fetal akinesia deformation sequence 1;C1850792:Congenital myasthenic syndrome 10 Pathogenic:1
Jan 12, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change results in a frameshift in the DOK7 gene (p.Ser422Leufs*97). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 83 amino acid(s) of the DOK7 protein and extend the protein by 13 additional amino acid residues. This variant is present in population databases (rs751257124, gnomAD 0.02%). This frameshift has been observed in individual(s) with congenital myasthenic syndrome and fetal akinesia deformation sequence (PMID: 16917026, 21850686, 22661499). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 1274). For these reasons, this variant has been classified as Pathogenic. -

Fetal akinesia deformation sequence 1 Pathogenic:1
May 28, 2019
Mendelics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Congenital myasthenic syndrome Pathogenic:1
Feb 28, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: DOK7 c.1263dupC (p.Ser422LeufsX97) causes a frameshift which results in an extension of the protein. The variant allele was found at a frequency of 7.6e-05 in 237478 control chromosomes (gnomAD). This frequency is not higher than expected for a pathogenic variant in DOK7 causing Congenital myasthenic syndrome (7.6e-05 vs 0.0014), allowing no conclusion about variant significance. c.1263dupC has been reported in the literature in compound heterozygous and homozygous individuals affected with Congenital myasthenic syndrome (Selcen_2008, Anderson_2008). These data indicate that the variant is very likely to be associated with disease. Two ClinVar submitters (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

DOK7-related disorder Pathogenic:1
Dec 11, 2023
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The DOK7 c.1263dupC variant is predicted to result in a frameshift and premature protein termination (p.Ser422Leufs*97). This variant has been reported in individuals with autosomal recessive congenital myasthenic syndrome (Beeson et al. 2006. PubMed ID: 16917026; Anderson et al. 2008. PubMed ID: 18161030; Cossins et al. 2012. PubMed ID: 22661499). It has also been reported in the homozygous state in a case of fetal akinesia deformation sequence (Table 1, Bruno et al. 2011. PubMed ID: 21850686). This variant is reported in 0.017% of alleles in individuals of African descent in gnomAD. Frameshift variants in DOK7 are expected to be pathogenic. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
0.080
Mutation Taster
=7/193
disease causing (ClinVar)

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: rs606231129; hg19: chr4-3494969; COSMIC: COSV60772076; COSMIC: COSV60772076; API