chr2-232526250-CT-C

Variant names:

• chr2-232526250-CT-C
• NM_000751.3:c.36delT

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000751.3(CHRND):​c.36delT​(p.Ala13ProfsTer10) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: CHRND NM_000751.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -5.07
• Publications: 0 publications found

Genes affected

CHRND (HGNC:1965): (cholinergic receptor nicotinic delta subunit) The acetylcholine receptor of muscle has 5 subunits of 4 different types: 2 alpha and 1 each of beta, gamma and delta subunits. After acetylcholine binding, the receptor undergoes an extensive conformation change that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. Defects in this gene are a cause of multiple pterygium syndrome lethal type (MUPSL), congenital myasthenic syndrome slow-channel type (SCCMS), and congenital myasthenic syndrome fast-channel type (FCCMS). Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2015]

CHRND Gene-Disease associations (from GenCC):

• congenital myasthenic syndrome 3A

  Inheritance: AD Classification: STRONG Submitted by: PanelApp Australia, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• congenital myasthenic syndrome 3B

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Genomics England PanelApp
• congenital myasthenic syndrome 3C

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• lethal multiple pterygium syndrome

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• postsynaptic congenital myasthenic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 41 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-232526250-CT-C is Pathogenic according to our data. Variant chr2-232526250-CT-C is described in ClinVar as [Pathogenic]. Clinvar id is 2843903.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRND	NM_000751.3	c.36delT	p.Ala13ProfsTer10	frameshift_variant	Exon 1 of 12	ENST00000258385.8	NP_000742.1
CHRND	NM_001256657.2	c.36delT	p.Ala13ProfsTer10	frameshift_variant	Exon 1 of 11		NP_001243586.1
CHRND	NM_001311196.2	c.-236delT		5_prime_UTR_variant	Exon 1 of 12		NP_001298125.1
CHRND	NM_001311195.2	c.-236delT		5_prime_UTR_variant	Exon 1 of 10		NP_001298124.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRND	ENST00000258385.8	c.36delT	p.Ala13ProfsTer10	frameshift_variant	Exon 1 of 12	1	NM_000751.3	ENSP00000258385.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Lethal multiple pterygium syndrome Pathogenic:1

Aug 12, 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.Ala13Profs*10) in the CHRND gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CHRND are known to be pathogenic (PMID: 11435464, 25264167). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CHRND-related conditions. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		-5.1
Mutation Taster		=15/185	disease causing (fs/PTC)

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

hg19: chr2-233390960;