rs797044677

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_005199.5(CHRNG):​c.117dupC​(p.Asn40GlnfsTer96) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,613,918 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. N40N) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000086 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

CHRNG
NM_005199.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 1.21

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 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 2-232540049-A-AC is Pathogenic according to our data. Variant chr2-232540049-A-AC is described in ClinVar as [Pathogenic]. Clinvar id is 195239.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.117dupC p.Asn40GlnfsTer96 frameshift_variant Exon 2 of 12 ENST00000651502.1 NP_005190.4 P07510-1A0A6F7YAP6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNGENST00000651502.1 linkc.117dupC p.Asn40GlnfsTer96 frameshift_variant Exon 2 of 12 NM_005199.5 ENSP00000498757.1 P07510-1
CHRNGENST00000389492.3 linkc.117dupC p.Asn40GlnfsTer86 frameshift_variant Exon 2 of 11 1 ENSP00000374143.3 P07510-2
CHRNGENST00000485094.1 linkn.138dupC non_coding_transcript_exon_variant Exon 2 of 5 1

Frequencies

GnomAD3 genomes
AF:
0.0000855
AC:
13
AN:
152042
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000266
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000480
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251316
AF XY:
0.0000294
show subpopulations
Gnomad AFR exome
AF:
0.000246
Gnomad AMR exome
AF:
0.0000579
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000116
AC:
17
AN:
1461876
Hom.:
0
Cov.:
33
AF XY:
0.0000138
AC XY:
10
AN XY:
727242
show subpopulations
African (AFR)
AF:
0.000299
AC:
10
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
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:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112000
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000855
AC:
13
AN:
152042
Hom.:
0
Cov.:
33
AF XY:
0.0000539
AC XY:
4
AN XY:
74246
show subpopulations
African (AFR)
AF:
0.000266
AC:
11
AN:
41380
American (AMR)
AF:
0.0000655
AC:
1
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67996
Other (OTH)
AF:
0.000480
AC:
1
AN:
2082
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.529
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000434
Hom.:
0
Bravo
AF:
0.0000982

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:3
Dec 16, 2014
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 13, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 31589614, 33820833, 24319099, 32587836) -

Jan 28, 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.Asn40Glnfs*96) 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 (rs752475887, gnomAD 0.02%). This premature translational stop signal has been observed in individual(s) with clinical features of CHRNG-related conditions (PMID: 24319099). This variant is also known as c.117_118insC. ClinVar contains an entry for this variant (Variation ID: 195239). For these reasons, this variant has been classified as Pathogenic. -

Autosomal recessive multiple pterygium syndrome Pathogenic:2
Apr 20, 2023
Duke University Health System Sequencing Clinic, Duke University Health System
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Jan 01, 2025
Center of Human Genetics, Hôpital Erasme
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Pathogenic:1
Sep 18, 2017
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Lethal multiple pterygium syndrome Pathogenic:1
Oct 15, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: CHRNG c.117dupC (p.Asn40GlnfsX96) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 2.4e-05 in 251316 control chromosomes. c.117dupC has been reported in the literature in individuals affected with Lethal Multiple Pterygium Syndrome - CHRNG Related (Laquerriere_2014). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 33820833). ClinVar contains an entry for this variant (Variation ID: 195239). Based on the evidence outlined above, the variant was classified as pathogenic. -

Autosomal recessive multiple pterygium syndrome;C1854678:Lethal multiple pterygium syndrome Pathogenic:1
Feb 06, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
1.2
Mutation Taster
=4/196
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

Publications

Other links and lift over

dbSNP: rs797044677; hg19: chr2-233404759; API