19-38580497-T-C

Position:

• chr19-38580497-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PP3_Moderate PS4_Supporting PM1_Supporting

This summary comes from the ClinGen Evidence Repository: This pathogenicity assessment is relevant only for malignant hyperthermia susceptibility (MHS) inherited in an autosomal dominant pattern. Variants in RYR1 can also cause other myopathies inherited in an autosomal dominant pattern or in an autosomal recessive pattern. Some of these disorders may predispose individuals to malignant hyperthermia. RYR1 variants may also contribute to a malignant hyperthermia reaction in combination with other genetic and non-genetic factors and the clinician needs to consider such factors in making management decisions.This sequence variant predicts a substitution of methionine with threonine at codon 4880 of the RYR1 protein, p.(Met4880Thr). This variant was not present in a large population database (gnomAD) at the time this variant was interpreted. This variant has been reported in an individual with a personal or family history of an MH episode and a positive in vitro contracture test (IVCT) or caffeine halothane contracture test (CHCT) result (if the proband was unavailable for testing, a positive diagnostic test result in a mutation-positive relative was counted), PS4_Supporting (PMID:15731587). No functional studies were identified for this variant. This variant resides in a region of RYR1 considered to be a hotspot for pathogenic variants that contribute to MHS, PM1_Supporting (PMID:21118704). A REVEL score >0.85 (0.956) supports a pathogenic status for this variant, PP3_Moderate. This variant has been classified as a Variant of Unknown Significance. Criteria implemented: PS4_Supporting, PM1_Supporting, PP3_Moderate. LINK:https://erepo.genome.network/evrepo/ui/classification/CA024202/MONDO:0018493/012

• Frequency: Genomes: not found (cov: 31)
• Consequence: RYR1 NM_000540.3 missense
• Clinical Significance: Uncertain significance reviewed by expert panel U:2 O:1
• Conservation: PhyloP100: 8.01

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RYR1	NM_000540.3	c.14639T>C	p.Met4880Thr	missense_variant	101/106	ENST00000359596.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RYR1	ENST00000359596.8	c.14639T>C	p.Met4880Thr	missense_variant	101/106	5	NM_000540.3	A2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

RYR1-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 08, 2023

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 4880 of the RYR1 protein (p.Met4880Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with malignant hyperthermia (PMID: 15731587). ClinVar contains an entry for this variant (Variation ID: 133082). 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 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. -

Malignant hyperthermia of anesthesia Uncertain:1

Uncertain significance, reviewed by expert panel

curation

ClinGen Malignant Hyperthermia Susceptibility Variant Curation Expert Panel, ClinGen

Apr 06, 2023

This pathogenicity assessment is relevant only for malignant hyperthermia susceptibility (MHS) inherited in an autosomal dominant pattern. Variants in RYR1 can also cause other myopathies inherited in an autosomal dominant pattern or in an autosomal recessive pattern. Some of these disorders may predispose individuals to malignant hyperthermia. RYR1 variants may also contribute to a malignant hyperthermia reaction in combination with other genetic and non-genetic factors and the clinician needs to consider such factors in making management decisions. This sequence variant predicts a substitution of methionine with threonine at codon 4880 of the RYR1 protein, p.(Met4880Thr). This variant was not present in a large population database (gnomAD) at the time this variant was interpreted. This variant has been reported in an individual with a personal or family history of an MH episode and a positive in vitro contracture test (IVCT) or caffeine halothane contracture test (CHCT) result (if the proband was unavailable for testing, a positive diagnostic test result in a mutation-positive relative was counted), PS4_Supporting (PMID:15731587). No functional studies were identified for this variant. This variant resides in a region of RYR1 considered to be a hotspot for pathogenic variants that contribute to MHS, PM1_Supporting (PMID: 21118704). A REVEL score >0.85 (0.956) supports a pathogenic status for this variant, PP3_Moderate. This variant has been classified as a Variant of Unknown Significance. Criteria implemented: PS4_Supporting, PM1_Supporting, PP3_Moderate. -

not provided Other:1

not provided, no classification provided

literature only

Leiden Muscular Dystrophy (RYR1)

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Benign	22
DANN	Benign	0.75
DEOGEN2	Pathogenic	0.92	.;D
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.84	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Pathogenic	3.1	.;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-5.2	D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D
Polyphen		0.98	D;D
Vest4		0.95
MutPred		0.80		.;Loss of helix (P = 0.0068);
MVP		0.96
MPC		0.77
ClinPred		0.99	D
GERP RS		4.8
Varity_R		0.93
gMVP		1.0

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: rs193922883; hg19: chr19-39071137;