NM_005199.5:c.202C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_005199.5(CHRNG):​c.202C>T​(p.Arg68*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,614,048 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

CHRNG
NM_005199.5 stop_gained

Scores

2
4
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 1.19

Publications

3 publications found
Variant links:
Genes affected
CHRNG (HGNC:1967): (cholinergic receptor nicotinic gamma subunit) The mammalian muscle-type acetylcholine receptor is a transmembrane pentameric glycoprotein with two alpha subunits, one beta, one delta, and one epsilon (in adult skeletal muscle) or gamma (in fetal and denervated muscle) subunit. This gene, which encodes the gamma subunit, is expressed prior to the thirty-third week of gestation in humans. The gamma subunit of the acetylcholine receptor plays a role in neuromuscular organogenesis and ligand binding and disruption of gamma subunit expression prevents the correct localization of the receptor in cell membranes. Mutations in this gene cause Escobar syndrome and a lethal form of multiple pterygium syndrome. Muscle-type acetylcholine receptor is the major antigen in the autoimmune disease myasthenia gravis.[provided by RefSeq, Sep 2009]
CHRNG Gene-Disease associations (from GenCC):
  • autosomal recessive multiple pterygium syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Orphanet
  • CHRNG-associated hypo-akinesia disorder of prenatal onset
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • lethal multiple pterygium syndrome
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Orphanet
  • transient neonatal myasthenia gravis
    Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 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 2-232540387-C-T is Pathogenic according to our data. Variant chr2-232540387-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 548021.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNGNM_005199.5 linkc.202C>T p.Arg68* stop_gained Exon 3 of 12 ENST00000651502.1 NP_005190.4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNGENST00000651502.1 linkc.202C>T p.Arg68* stop_gained Exon 3 of 12 NM_005199.5 ENSP00000498757.1
CHRNGENST00000389492.3 linkc.202C>T p.Arg68* stop_gained Exon 3 of 11 1 ENSP00000374143.3
CHRNGENST00000485094.1 linkn.223C>T non_coding_transcript_exon_variant Exon 3 of 5 1

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152100
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
251408
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000287
AC:
42
AN:
1461830
Hom.:
0
Cov.:
32
AF XY:
0.0000220
AC XY:
16
AN XY:
727228
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000333
AC:
37
AN:
1111976
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
3
7
10
14
17
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152218
Hom.:
0
Cov.:
33
AF XY:
0.0000403
AC XY:
3
AN XY:
74430
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41528
American (AMR)
AF:
0.00
AC:
0
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000194
AC:
1
AN:
5164
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68000
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.513
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000406
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive multiple pterygium syndrome;C1854678:Lethal multiple pterygium syndrome Pathogenic:2
Jan 12, 2018
Mayo Clinic Laboratories, Mayo Clinic
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 20, 2023
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive multiple pterygium syndrome Pathogenic:1
Apr 04, 2024
Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Scoliosis;C1837407:Ankle flexion contracture;C4025173:Arthrogryposis-like hand anomaly Pathogenic:1
Oct 16, 2019
Center for Reproductive Medicine, Peking University Third Hospital
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Lethal multiple pterygium syndrome Pathogenic:1
Dec 31, 2019
Breakthrough Genomics, Breakthrough Genomics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been previously reported in the literature. However, other truncating variants such as: W139X, R448X, Q18X and R46X have been detected in families with Escobar syndrome/ multiple pterygium syndrome [PMID: 16826520, 16826531]. -

not provided Pathogenic:1
Jan 18, 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.Arg68*) in the CHRNG gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CHRNG are known to be pathogenic (PMID: 16826520). This variant is present in population databases (rs764266722, gnomAD 0.004%). This premature translational stop signal has been observed in individual(s) with multiple pteygium syndrome (PMID: 22167768). ClinVar contains an entry for this variant (Variation ID: 548021). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.55
D
BayesDel_noAF
Pathogenic
0.44
CADD
Pathogenic
39
DANN
Uncertain
1.0
Eigen
Uncertain
0.55
Eigen_PC
Uncertain
0.35
FATHMM_MKL
Uncertain
0.86
D
PhyloP100
1.2
Vest4
0.87
GERP RS
3.0
Mutation Taster
=4/196
disease causing (ClinVar)

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: rs764266722; hg19: chr2-233405097; COSMIC: COSV51329061; COSMIC: COSV51329061; API