2-232529965-C-T

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BS1_SupportingBS2

The NM_000751.3(CHRND):​c.646C>T​(p.Arg216Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000139 in 1,614,110 control chromosomes in the GnomAD database, including 3 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R216Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000098 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00014 ( 3 hom. )

Consequence

CHRND
NM_000751.3 missense

Scores

4
12
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2B:1

Conservation

PhyloP100: 0.810

Publications

5 publications found
Variant links:
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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BS1
Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.0000985 (15/152302) while in subpopulation SAS AF = 0.00228 (11/4826). AF 95% confidence interval is 0.00128. There are 0 homozygotes in GnomAd4. There are 13 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High Homozygotes in GnomAdExome4 at 3 AR,AD gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNDNM_000751.3 linkc.646C>T p.Arg216Trp missense_variant Exon 7 of 12 ENST00000258385.8 NP_000742.1 Q07001-1
CHRNDNM_001256657.2 linkc.601C>T p.Arg201Trp missense_variant Exon 6 of 11 NP_001243586.1 Q07001-2
CHRNDNM_001311196.2 linkc.343C>T p.Arg115Trp missense_variant Exon 7 of 12 NP_001298125.1 Q07001
CHRNDNM_001311195.2 linkc.238+1309C>T intron_variant Intron 5 of 9 NP_001298124.1 Q07001B4E3W4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNDENST00000258385.8 linkc.646C>T p.Arg216Trp missense_variant Exon 7 of 12 1 NM_000751.3 ENSP00000258385.3 Q07001-1

Frequencies

GnomAD3 genomes
AF:
0.0000986
AC:
15
AN:
152184
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.00228
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000217
AC:
54
AN:
249248
AF XY:
0.000282
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.0000358
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000143
AC:
209
AN:
1461808
Hom.:
3
Cov.:
32
AF XY:
0.000183
AC XY:
133
AN XY:
727206
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.00179
AC:
154
AN:
86256
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53368
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000333
AC:
37
AN:
1111994
Other (OTH)
AF:
0.000248
AC:
15
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
14
27
41
54
68
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000985
AC:
15
AN:
152302
Hom.:
0
Cov.:
32
AF XY:
0.000175
AC XY:
13
AN XY:
74482
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41566
American (AMR)
AF:
0.00
AC:
0
AN:
15302
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5174
South Asian (SAS)
AF:
0.00228
AC:
11
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.515
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000405
Hom.:
0
Bravo
AF:
0.0000378
ExAC
AF:
0.000264
AC:
32
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.000109
EpiControl
AF:
0.000119

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2Benign:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Lethal multiple pterygium syndrome Uncertain:1
Jan 11, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 216 of the CHRND protein (p.Arg216Trp). This variant is present in population databases (rs777271963, gnomAD 0.2%). This variant has not been reported in the literature in individuals affected with CHRND-related conditions. ClinVar contains an entry for this variant (Variation ID: 570038). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on CHRND protein function. 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. -

not provided Uncertain:1
Apr 17, 2023
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

CHRND-related disorder Benign:1
May 25, 2022
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.46
BayesDel_addAF
Benign
-0.053
T
BayesDel_noAF
Uncertain
0.13
CADD
Uncertain
24
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.55
.;D
Eigen
Uncertain
0.59
Eigen_PC
Uncertain
0.54
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Pathogenic
0.98
D;D
M_CAP
Uncertain
0.15
D
MetaRNN
Uncertain
0.46
T;T
MetaSVM
Uncertain
0.17
D
MutationAssessor
Uncertain
2.8
.;M
PhyloP100
0.81
PrimateAI
Benign
0.45
T
PROVEAN
Pathogenic
-4.8
D;D
REVEL
Pathogenic
0.66
Sift
Uncertain
0.0040
D;D
Sift4G
Uncertain
0.022
D;D
Polyphen
1.0
.;D
Vest4
0.74
MutPred
0.69
.;Loss of disorder (P = 0.0366);
MVP
1.0
MPC
0.89
ClinPred
0.34
T
GERP RS
4.1
Varity_R
0.52
gMVP
0.79
Mutation Taster
=73/27
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.060
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs777271963; hg19: chr2-233394675; COSMIC: COSV51320588; COSMIC: COSV51320588; API