NM_000751.3:c.730C>T

Variant names:

• chr2-232530049-C-T
• rs376642208
• NM_000751.3:c.730C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PS3 PP3_Strong PP5

The NM_000751.3(CHRND):​c.730C>T​(p.Arg244Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,614,030 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). ClinVar reports functional evidence for this variant: "SCV001203242: Experimental studies have shown that this missense change affects CHRND function (PMID:32360402).". Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R244H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: CHRND NM_000751.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 1.58
• Publications: 2 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: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• congenital myasthenic syndrome 3B

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

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

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV001203242: Experimental studies have shown that this missense change affects CHRND function (PMID: 32360402).
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984
• PP5: Variant 2-232530049-C-T is Pathogenic according to our data. Variant chr2-232530049-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 585671.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000751.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRND	NM_000751.3	MANE Select	c.730C>T	p.Arg244Cys	missense	Exon 7 of 12	NP_000742.1	Q07001-1
	CHRND	NM_001256657.2		c.685C>T	p.Arg229Cys	missense	Exon 6 of 11	NP_001243586.1	Q07001-2
	CHRND	NM_001311196.2		c.427C>T	p.Arg143Cys	missense	Exon 7 of 12	NP_001298125.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRND	ENST00000258385.8	TSL:1 MANE Select	c.730C>T	p.Arg244Cys	missense	Exon 7 of 12	ENSP00000258385.3	Q07001-1
	CHRND	ENST00000543200.5	TSL:2	c.685C>T	p.Arg229Cys	missense	Exon 6 of 11	ENSP00000438380.1	Q07001-2
	CHRND	ENST00000955151.1		c.619+1078C>T		intron	N/A	ENSP00000625210.1

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152156 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251290 AF XY: 0.0000221

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000253 AC: 37 AN: 1461874 Hom.: 0 Cov.: 32 AF XY: 0.0000261 AC XY: 19 AN XY: 727232

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000306 AC: 34 AN: 1112010

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 152156 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74326

African (AFR) AF: 0.00 AC: 0 AN: 41438

American (AMR) AF: 0.0000654 AC: 1 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.0000676 Hom.: 0

Bravo AF: 0.0000151

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.0000165 AC: 2

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
1	-	-	Lethal multiple pterygium syndrome (1)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.51
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.86	D
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.97	D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.4	H
PhyloP100		1.6
PrimateAI	Uncertain	0.58	T
PROVEAN	Pathogenic	-7.2	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.99
MVP		1.0
MPC		1.0
ClinPred		1.0	D
GERP RS		4.3
Varity_R		0.90
gMVP		0.94
Mutation Taster		=3/97	disease causing (ClinVar)

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

dbSNP: rs376642208; hg19: chr2-233394759; COSMIC: COSV51317330; COSMIC: COSV51317330;