9-110697395-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_005592.4(MUSK):​c.557G>C​(p.Gly186Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000533 in 1,612,906 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. G186E) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000058 ( 0 hom. )

Consequence

MUSK
NM_005592.4 missense

Scores

9
7
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 8.43

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.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.753

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005592.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MUSK
NM_005592.4
MANE Select
c.557G>Cp.Gly186Ala
missense
Exon 5 of 15NP_005583.1
MUSK
NM_001166280.2
c.557G>Cp.Gly186Ala
missense
Exon 5 of 14NP_001159752.1
MUSK
NM_001166281.2
c.557G>Cp.Gly186Ala
missense
Exon 5 of 13NP_001159753.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MUSK
ENST00000374448.9
TSL:5 MANE Select
c.557G>Cp.Gly186Ala
missense
Exon 5 of 15ENSP00000363571.4
MUSK
ENST00000416899.7
TSL:5
c.557G>Cp.Gly186Ala
missense
Exon 5 of 14ENSP00000393608.3
MUSK
ENST00000189978.10
TSL:5
c.557G>Cp.Gly186Ala
missense
Exon 5 of 14ENSP00000189978.6

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152070
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000442
AC:
11
AN:
248594
AF XY:
0.0000371
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000878
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000709
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000575
AC:
84
AN:
1460836
Hom.:
0
Cov.:
31
AF XY:
0.0000564
AC XY:
41
AN XY:
726742
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33464
American (AMR)
AF:
0.0000896
AC:
4
AN:
44658
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26112
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39682
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86090
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53378
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000675
AC:
75
AN:
1111336
Other (OTH)
AF:
0.0000829
AC:
5
AN:
60348
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.484
Heterozygous variant carriers
0
4
8
13
17
21
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000132
AC:
2
AN:
152070
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74270
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41418
American (AMR)
AF:
0.0000655
AC:
1
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68000
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.0000302
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000241
AC:
2
ExAC
AF:
0.0000662
AC:
8
EpiCase
AF:
0.0000548
EpiControl
AF:
0.000179

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Jul 11, 2024
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Sep 16, 2025
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 25537362)

Inborn genetic diseases Uncertain:1
Aug 21, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.557G>C (p.G186A) alteration is located in exon 5 (coding exon 5) of the MUSK gene. This alteration results from a G to C substitution at nucleotide position 557, causing the glycine (G) at amino acid position 186 to be replaced by an alanine (A). 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
Aug 23, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 186 of the MUSK protein (p.Gly186Ala). This variant is present in population databases (rs373304727, gnomAD 0.009%). 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: 432807). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt MUSK protein function with a positive predictive value of 80%. 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 v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.62
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Pathogenic
0.25
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Benign
0.40
T
Eigen
Pathogenic
0.92
Eigen_PC
Pathogenic
0.91
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D
M_CAP
Benign
0.029
D
MetaRNN
Pathogenic
0.75
D
MetaSVM
Uncertain
-0.17
T
MutationAssessor
Pathogenic
3.0
M
PhyloP100
8.4
PrimateAI
Uncertain
0.69
T
PROVEAN
Uncertain
-2.6
D
REVEL
Uncertain
0.61
Sift
Pathogenic
0.0
D
Sift4G
Uncertain
0.012
D
Polyphen
1.0
D
Vest4
0.93
MVP
0.80
MPC
0.61
ClinPred
0.55
D
GERP RS
5.9
Varity_R
0.80
gMVP
0.86
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: rs373304727; hg19: chr9-113459675; API