rs1555769826

Positions:

• chr19-38458123-G-A
• chr19-38458123-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1 PM2 PP2 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. 12/21 in silico tools predict 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

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 3 ACMG points.

• PM1: In a domain B30.2/SPRY 1 (size 216) in uniprot entity RYR1_HUMAN there are 8 pathogenic changes around while only 1 benign (89%) in NM_000540.3
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), RYR1. . Gene score misZ 1.918 (greater than the threshold 3.09). Trascript score misZ 3.9788 (greater than threshold 3.09). GenCC has associacion of gene with King-Denborough syndrome, congenital multicore myopathy with external ophthalmoplegia, autosomal recessive centronuclear myopathy, RYR1-related myopathy, lethal multiple pterygium syndrome, malignant hyperthermia of anesthesia, benign Samaritan congenital myopathy, malignant hyperthermia, susceptibility to, 1, congenital myopathy with myasthenic-like onset, central core myopathy.
• BP4: Computational evidence support a benign effect (MetaRNN=0.1448814).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RYR1	NM_000540.3	c.1998G>A	p.Met666Ile	missense_variant	18/106	ENST00000359596.8	NP_000531.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RYR1	ENST00000359596.8	c.1998G>A	p.Met666Ile	missense_variant	18/106	5	NM_000540.3	ENSP00000352608.2
RYR1	ENST00000355481.8	c.1998G>A	p.Met666Ile	missense_variant	18/105	1		ENSP00000347667.3
RYR1	ENST00000599547.6	n.1998G>A		non_coding_transcript_exon_variant	18/80	2		ENSP00000471601.2

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 20, 2017

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. 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. This variant has not been reported in the literature in individuals with RYR1-related disease. This variant is not present in population databases (ExAC no frequency). 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. -

Computational scores

Source: dbNSFP v4.3

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;D
M_CAP	Benign	0.0091	T
MetaRNN	Benign	0.14	T;T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	-0.57	N;N
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-0.89	N;N
REVEL	Uncertain	0.31
Sift	Benign	0.76	T;T
Polyphen		0.12	B;B
Vest4		0.50
MutPred		0.49		Loss of catalytic residue at M666 (P = 0.0731);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

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555769826; hg19: chr19-38948763;