9-110668862-G-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_005592.4(MUSK):c.-43G>A variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000947 in 1,510,240 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000091 (0 hom.)
• Consequence: MUSK NM_005592.4 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.526

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]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.68).
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.000131 (20/152270) while in subpopulation EAS AF= 0.00366 (19/5186). AF 95% confidence interval is 0.0024. There are 0 homozygotes in gnomad4. There are 15 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MUSK	NM_005592.4	c.-43G>A		5_prime_UTR_variant	1/15	ENST00000374448.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MUSK	ENST00000374448.9	c.-43G>A		5_prime_UTR_variant	1/15	5	NM_005592.4	P4
MUSK	ENST00000189978.10	c.-43G>A		5_prime_UTR_variant	1/14	5
MUSK	ENST00000416899.7	c.-43G>A		5_prime_UTR_variant	1/14	5		A1

Frequencies

GnomAD3 genomes AF: 0.000131 AC: 20 AN: 152152 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: 0.00366

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

GnomAD3 exomes AF: 0.000303 AC: 75 AN: 247630 Hom.: 0 AF XY: 0.000276 AC XY: 37 AN XY: 134290

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000585

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00379

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000891

Gnomad OTH exome AF: 0.000667

GnomAD4 exome AF: 0.0000906 AC: 123 AN: 1357970 Hom.: 0 Cov.: 21 AF XY: 0.0000955 AC XY: 65 AN XY: 680716

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000450

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00246

Gnomad4 SAS exome AF: 0.0000119

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000786

Gnomad4 OTH exome AF: 0.000281

GnomAD4 genome AF: 0.000131 AC: 20 AN: 152270 Hom.: 0 Cov.: 32 AF XY: 0.000201 AC XY: 15 AN XY: 74442

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00366

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000434 Hom.: 0

Bravo AF: 0.0000642

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital myasthenic syndrome 9 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.68
Cadd	Benign	6.4
Dann	Benign	0.90

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: rs116884176; hg19: chr9-113431142; COSMIC: COSV51897511;