rs933599635

Variant names:

• chr19-38580376-A-T
• rs933599635
• NM_000540.3:c.14518A>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000540.3(RYR1):​c.14518A>T​(p.Met4840Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,810 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. M4840R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: RYR1 NM_000540.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.17
• Publications: 0 publications found

Genes affected

RYR1 (HGNC:10483): (ryanodine receptor 1) This gene encodes a ryanodine receptor found in skeletal muscle. The encoded protein functions as a calcium release channel in the sarcoplasmic reticulum but also serves to connect the sarcoplasmic reticulum and transverse tubule. Mutations in this gene are associated with malignant hyperthermia susceptibility, central core disease, and minicore myopathy with external ophthalmoplegia. Alternatively spliced transcripts encoding different isoforms have been described. [provided by RefSeq, Jul 2008]

RYR1 Gene-Disease associations (from GenCC):

• malignant hyperthermia, susceptibility to, 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Genomics England PanelApp, Ambry Genetics
• congenital multicore myopathy with external ophthalmoplegia

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp
• RYR1-related myopathy

  Inheritance: AR, AD Classification: DEFINITIVE Submitted by: ClinGen
• central core myopathy

  Inheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp
• King-Denborough syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• malignant hyperthermia of anesthesia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive centronuclear myopathy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• benign Samaritan congenital myopathy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• congenital myopathy with myasthenic-like onset

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• lethal multiple pterygium syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_000540.3
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RYR1	NM_000540.3	c.14518A>T	p.Met4840Leu	missense_variant	Exon 101 of 106	ENST00000359596.8	NP_000531.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RYR1	ENST00000359596.8	c.14518A>T	p.Met4840Leu	missense_variant	Exon 101 of 106	5	NM_000540.3	ENSP00000352608.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461810 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727206

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53366

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111998

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Oct 30, 2013

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 17, 2017

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The M4840L variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The M4840L variant is not observed in large population cohorts (Lek et al., 2016). This variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. This substitution occurs at a position where amino acids with similar properties to Methionine are tolerated across species. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. -

RYR1-related disorder Uncertain:1

Oct 04, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 4840 of the RYR1 protein (p.Met4840Leu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with RYR1-related conditions. ClinVar contains an entry for this variant (Variation ID: 452823). 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 not expected to disrupt RYR1 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	Benign	0.22
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Benign	22
DANN	Benign	0.89
DEOGEN2	Uncertain	0.54	.;D
Eigen	Benign	-0.67
Eigen_PC	Benign	-0.37
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.59	T;T
M_CAP	Uncertain	0.096	D
MetaRNN	Uncertain	0.44	T;T
MetaSVM	Uncertain	0.15	D
MutationAssessor	Benign	-1.7	.;N
PhyloP100		2.2
PrimateAI	Pathogenic	0.81	D
PROVEAN	Benign	-0.010	N;N
REVEL	Uncertain	0.49
Sift	Benign	1.0	T;T
Polyphen		0.0020	B;B
Vest4		0.77
MutPred		0.62		.;Loss of methylation at K4836 (P = 0.0582);
MVP		0.87
MPC		0.63
ClinPred		0.49	T
GERP RS		4.6
Varity_R		0.25
gMVP		0.90
Mutation Taster		=27/73	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

Other links and lift over

dbSNP: rs933599635; hg19: chr19-39071016;