4-3489685-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_173660.5(DOK7):c.661C>T(p.Pro221Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000958 in 1,565,308 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign 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. P221A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000092 (0 hom.)
• Consequence: DOK7 NM_173660.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0130

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.047454834).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DOK7	NM_173660.5	c.661C>T	p.Pro221Ser	missense_variant	6/7	ENST00000340083.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DOK7	ENST00000340083.6	c.661C>T	p.Pro221Ser	missense_variant	6/7	1	NM_173660.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 152088 Hom.: 0 Cov.: 32

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: 0.000188

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000230 AC: 4 AN: 173762 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 92676

Gnomad AFR exome AF: 0.0000996

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.000186

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000920 AC: 13 AN: 1413220 Hom.: 0 Cov.: 31 AF XY: 0.00000716 AC XY: 5 AN XY: 698592

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000124

Gnomad4 FIN exome AF: 0.000183

Gnomad4 NFE exome AF: 0.00000276

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 152088 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74278

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.000188

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

ESP6500AA AF: 0.000230 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.00000849 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Fetal akinesia deformation sequence 1;C1850792:Congenital myasthenic syndrome 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 05, 2019

This sequence change replaces proline with serine at codon 221 of the DOK7 protein (p.Pro221Ser). The proline residue is weakly conserved and there is a moderate physicochemical difference between proline and serine. This variant is present in population databases (rs377167511, ExAC 0.03%). This variant has not been reported in the literature in individuals with DOK7-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The serine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.061
BayesDel_addAF	Benign	-0.26	T
BayesDel_noAF	Benign	-0.39
Cadd	Benign	7.9
Dann	Benign	0.96
DEOGEN2	Benign	0.024	T;.
Eigen	Benign	-0.69
Eigen_PC	Benign	-0.84
FATHMM_MKL	Benign	0.0095	N
LIST_S2	Benign	0.65	T;T
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.047	T;T
MetaSVM	Benign	-0.36	T
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Uncertain	0.51	T
PROVEAN	Benign	-0.66	N;.
REVEL	Benign	0.099
Sift	Benign	0.86	T;.
Sift4G	Benign	0.84	T;.
Polyphen		0.0030	B;.
Vest4		0.20
MVP		0.80
MPC		0.0045
ClinPred		0.026	T
GERP RS		0.43
Varity_R		0.021
gMVP		0.25

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

Other links and lift over

dbSNP: rs377167511; hg19: chr4-3491412; COSMIC: COSV60773776;