4-3493130-G-T

Variant names:

• chr4-3493130-G-T
• rs560463670
• NM_173660.5:c.1144G>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_173660.5(DOK7):​c.1144G>T​(p.Glu382*) variant causes a stop gained change. The variant allele was found at a frequency of 0.000000693 in 1,443,320 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. E382E) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: DOK7 NM_173660.5 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.02
• Publications: 0 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 10 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DOK7	NM_173660.5	c.1144G>T	p.Glu382*	stop_gained	Exon 7 of 7	ENST00000340083.6	NP_775931.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DOK7	ENST00000340083.6	c.1144G>T	p.Glu382*	stop_gained	Exon 7 of 7	1	NM_173660.5	ENSP00000344432.5

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 6.93e-7 AC: 1 AN: 1443320 Hom.: 0 Cov.: 113 AF XY: 0.00 AC XY: 0 AN XY: 717032

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

African (AFR) AF: 0.00 AC: 0 AN: 33162

American (AMR) AF: 0.00 AC: 0 AN: 42744

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25814

East Asian (EAS) AF: 0.00 AC: 0 AN: 38588

South Asian (SAS) AF: 0.00 AC: 0 AN: 84120

European-Finnish (FIN) AF: 0.0000209 AC: 1 AN: 47734

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5752

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1105780

Other (OTH) AF: 0.00 AC: 0 AN: 59626

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.29
CADD	Pathogenic	54
DANN	Uncertain	0.99
Eigen	Pathogenic	0.78
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Uncertain	0.78	D
PhyloP100		6.0
Vest4		0.53
GERP RS		3.8
Mutation Taster		=19/181	disease causing (fs/PTC)

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

Other links and lift over

dbSNP: rs560463670; hg19: chr4-3494857;