chr2-232526228-G-T

Variant names:

• chr2-232526228-G-T
• rs1691455448
• NM_000751.3:c.13G>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000751.3(CHRND):​c.13G>T​(p.Val5Leu) 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. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: CHRND NM_000751.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.135
• 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: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.09583655).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRND	NM_000751.3	c.13G>T	p.Val5Leu	missense_variant	Exon 1 of 12	ENST00000258385.8	NP_000742.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRND	ENST00000258385.8	c.13G>T	p.Val5Leu	missense_variant	Exon 1 of 12	1	NM_000751.3	ENSP00000258385.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Lethal multiple pterygium syndrome Uncertain:1

Jun 20, 2023

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. 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 not expected to disrupt CHRND protein function. This variant has not been reported in the literature in individuals affected with CHRND-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 5 of the CHRND protein (p.Val5Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.089
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.49
CADD	Benign	12
DANN	Uncertain	0.98
DEOGEN2	Benign	0.068	.;.;T
Eigen	Benign	-0.97
Eigen_PC	Benign	-0.89
FATHMM_MKL	Benign	0.083	N
LIST_S2	Benign	0.69	T;T;T
M_CAP	Benign	0.025	T
MetaRNN	Benign	0.096	T;T;T
MetaSVM	Benign	-0.82	T
MutationAssessor	Benign	0.075	.;N;N
PhyloP100		0.14
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-0.020	N;N;N
REVEL	Benign	0.10
Sift	Benign	0.17	T;T;T
Sift4G	Benign	0.92	T;T;T
Polyphen		0.0	.;.;B
Vest4		0.089, 0.073
MutPred		0.34		Gain of glycosylation at P4 (P = 0.1302);Gain of glycosylation at P4 (P = 0.1302);Gain of glycosylation at P4 (P = 0.1302);
MVP		0.59
MPC		0.24
ClinPred		0.19	T
GERP RS		2.0
PromoterAI		0.038	Neutral
Varity_R		0.051
gMVP		0.36
Mutation Taster		=94/6	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1691455448; hg19: chr2-233390938;