19-38458123-G-A

Variant names:

• chr19-38458123-G-A
• rs1555769826
• NM_000540.3:c.1998G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000540.3(RYR1):​c.1998G>A​(p.Met666Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: RYR1 NM_000540.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.521
• 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 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000540.3
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1448814).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000540.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RYR1	NM_000540.3	MANE Select	c.1998G>A	p.Met666Ile	missense	Exon 18 of 106	NP_000531.2
	RYR1	NM_001042723.2		c.1998G>A	p.Met666Ile	missense	Exon 18 of 105	NP_001036188.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RYR1	ENST00000359596.8	TSL:5 MANE Select	c.1998G>A	p.Met666Ile	missense	Exon 18 of 106	ENSP00000352608.2
	RYR1	ENST00000355481.8	TSL:1	c.1998G>A	p.Met666Ile	missense	Exon 18 of 105	ENSP00000347667.3
	RYR1	ENST00000594335.6	TSL:1	n.1998G>A		non_coding_transcript_exon	Exon 18 of 103	ENSP00000470927.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

RYR1-related disorder Uncertain:1

Aug 20, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. This sequence change replaces methionine with isoleucine at codon 666 of the RYR1 protein (p.Met666Ile). The methionine residue is moderately conserved and there is a small physicochemical difference between methionine and isoleucine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with RYR1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.40
BayesDel_addAF	Benign	-0.027	T
BayesDel_noAF	Benign	-0.28
CADD	Benign	22
DANN	Uncertain	0.98
DEOGEN2	Benign	0.31	T
Eigen	Benign	-0.43
Eigen_PC	Benign	-0.24
FATHMM_MKL	Uncertain	0.80	D
LIST_S2	Uncertain	0.91	D
M_CAP	Benign	0.0091	T
MetaRNN	Benign	0.14	T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	-0.57	N
PhyloP100		0.52
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-0.89	N
REVEL	Uncertain	0.31
Sift	Benign	0.76	T
Polyphen		0.12	B
Vest4		0.50
MutPred		0.49		Loss of catalytic residue at M666 (P = 0.0731)
MVP		0.64
MPC		0.44
ClinPred		0.46	T
GERP RS		3.8
Varity_R		0.051
gMVP		0.43
Mutation Taster		=67/33	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1555769826; hg19: chr19-38948763;