rs754730206

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PP3_StrongBS1_Supporting

The NM_005592.4(MUSK):​c.2002C>T​(p.Arg668Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000192 in 1,613,692 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R668H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

MUSK
NM_005592.4 missense

Scores

9
9
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.80

Publications

1 publications found
Variant links:
Genes affected
MUSK (HGNC:7525): (muscle associated receptor tyrosine kinase) This gene encodes a muscle-specific tyrosine kinase receptor. The encoded protein may play a role in clustering of the acetylcholine receptor in the postsynaptic neuromuscular junction. Mutations in this gene have been associated with congenital myasthenic syndrome. Alternatively spliced transcript variants have been described.[provided by RefSeq, Oct 2009]
MUSK Gene-Disease associations (from GenCC):
  • congenital myasthenic syndrome 9
    Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
  • fetal akinesia deformation sequence 1
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
  • 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: Uncertain_significance. The variant received 3 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.943
BS1
Variant frequency is greater than expected in population amr. GnomAdExome4 allele frequency = 0.0000205 (30/1461700) while in subpopulation AMR AF = 0.000492 (22/44724). AF 95% confidence interval is 0.000333. There are 0 homozygotes in GnomAdExome4. There are 16 alleles in the male GnomAdExome4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MUSKNM_005592.4 linkc.2002C>T p.Arg668Cys missense_variant Exon 15 of 15 ENST00000374448.9 NP_005583.1 O15146-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MUSKENST00000374448.9 linkc.2002C>T p.Arg668Cys missense_variant Exon 15 of 15 5 NM_005592.4 ENSP00000363571.4 O15146-1
MUSKENST00000416899.7 linkc.1978C>T p.Arg660Cys missense_variant Exon 14 of 14 5 ENSP00000393608.3 A0A087WSY1
MUSKENST00000189978.10 linkc.1744C>T p.Arg582Cys missense_variant Exon 14 of 14 5 ENSP00000189978.6 O15146-2

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151992
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.0000120
AC:
3
AN:
249174
AF XY:
0.0000148
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
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:
0.000330
GnomAD4 exome
AF:
0.0000205
AC:
30
AN:
1461700
Hom.:
0
Cov.:
32
AF XY:
0.0000220
AC XY:
16
AN XY:
727132
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000492
AC:
22
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
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:
53398
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111864
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60374
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
2
4
7
9
11
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:
0.00000658
AC:
1
AN:
151992
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41386
American (AMR)
AF:
0.0000655
AC:
1
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4800
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10592
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67988
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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:
0.0000282
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.00000826
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Nov 29, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.2002C>T (p.R668C) alteration is located in exon 15 (coding exon 15) of the MUSK gene. This alteration results from a C to T substitution at nucleotide position 2002, causing the arginine (R) at amino acid position 668 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Fetal akinesia deformation sequence 1;C4225368:Congenital myasthenic syndrome 9 Uncertain:1
Oct 25, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 668 of the MUSK protein (p.Arg668Cys). This variant is present in population databases (rs754730206, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with MUSK-related conditions. ClinVar contains an entry for this variant (Variation ID: 476139). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt MUSK protein function. 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
Uncertain
0.55
BayesDel_addAF
Pathogenic
0.28
D
BayesDel_noAF
Pathogenic
0.24
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.56
D;.;.;.
Eigen
Uncertain
0.67
Eigen_PC
Uncertain
0.59
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.99
D;D;D;D
M_CAP
Uncertain
0.19
D
MetaRNN
Pathogenic
0.94
D;D;D;D
MetaSVM
Uncertain
0.73
D
MutationAssessor
Pathogenic
3.0
M;.;.;.
PhyloP100
4.8
PrimateAI
Uncertain
0.66
T
PROVEAN
Pathogenic
-5.3
D;.;.;.
REVEL
Pathogenic
0.85
Sift
Uncertain
0.011
D;.;.;.
Sift4G
Uncertain
0.0020
D;D;D;D
Polyphen
0.99
D;.;.;.
Vest4
0.92
MutPred
0.81
Loss of phosphorylation at S671 (P = 0.0621);.;.;.;
MVP
0.95
MPC
0.81
ClinPred
0.98
D
GERP RS
4.3
Varity_R
0.63
gMVP
0.75
Mutation Taster
=33/67
disease causing

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: rs754730206; hg19: chr9-113562660; COSMIC: COSV107205443; API