chr19-38442406-C-T

Variant names:

• chr19-38442406-C-T
• rs1346649518
• NM_000540.3:c.223C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_000540.3(RYR1):​c.223C>T​(p.Arg75*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,548 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: RYR1 NM_000540.3 stop_gained
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 2.16
• Publications: 1 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: Pathogenic. The variant received 11 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-38442406-C-T is Pathogenic according to our data. Variant chr19-38442406-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 544401.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RYR1	NM_000540.3	c.223C>T	p.Arg75*	stop_gained	Exon 3 of 106	ENST00000359596.8	NP_000531.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RYR1	ENST00000359596.8	c.223C>T	p.Arg75*	stop_gained	Exon 3 of 106	5	NM_000540.3	ENSP00000352608.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251252 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461548 Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3 AN XY: 727090

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.0000447 AC: 2 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111768

Other (OTH) AF: 0.00 AC: 0 AN: 60360

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000312 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

RYR1-related disorder Pathogenic:1

May 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg75*) in the RYR1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in RYR1 are known to be pathogenic (PMID: 23919265, 25960145, 28818389, 30611313). This variant is present in population databases (no rsID available, gnomAD 0.006%). 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: 544401). For these reasons, this variant has been classified as Pathogenic. -

Malignant hyperthermia, susceptibility to, 1 Uncertain:1

Apr 03, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant changes 1 nucleotide in exon 3 of the RYR1 gene, creating a premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has not been reported in individuals affected with RYR1-related disorders in the literature. This variant has been identified in 2/251252 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Loss of RYR1 function due to haploinsufficiency is not an established disease mechanism for autosomal dominant malignant hyperthermia, although it is associated with other phenotype(s) (ClinVar Variation ID: 544401). Due to insufficient evidence, this variant is classified as a Variant of Uncertain Significance for autosomal dominant malignant hyperthermia. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.62
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.46
FATHMM_MKL	Uncertain	0.92	D
PhyloP100		2.2
Vest4		0.89
GERP RS		3.7
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1346649518; hg19: chr19-38933046;