rs777219451

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM2PM5PP3_StrongPP5_Very_Strong

The NM_005199.5(CHRNG):​c.256C>T​(p.Arg86Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000329 in 1,612,138 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R86H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000036 ( 0 hom. )

Consequence

CHRNG
NM_005199.5 missense

Scores

13
5
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 2.99

Publications

0 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.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr2-232540618-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2458845.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.979
PP5
Variant 2-232540617-C-T is Pathogenic according to our data. Variant chr2-232540617-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 397615.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.256C>T p.Arg86Cys missense_variant Exon 4 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.256C>T p.Arg86Cys missense_variant Exon 4 of 12 NM_005199.5 ENSP00000498757.1 P07510-1
CHRNGENST00000389492.3 linkc.256C>T p.Arg86Cys missense_variant Exon 4 of 11 1 ENSP00000374143.3 P07510-2
CHRNGENST00000485094.1 linkn.277C>T non_coding_transcript_exon_variant Exon 4 of 5 1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152190
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:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000161
AC:
4
AN:
248786
AF XY:
0.0000223
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:
0.0000265
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000356
AC:
52
AN:
1459948
Hom.:
0
Cov.:
32
AF XY:
0.0000385
AC XY:
28
AN XY:
726398
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33472
American (AMR)
AF:
0.00
AC:
0
AN:
44684
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.000101
AC:
4
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86236
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51804
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5678
European-Non Finnish (NFE)
AF:
0.0000405
AC:
45
AN:
1111914
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60342
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.456
Heterozygous variant carriers
0
4
8
11
15
19
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:
0.00000657
AC:
1
AN:
152190
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74354
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41458
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.0000453
Hom.:
0
Bravo
AF:
0.0000416
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive multiple pterygium syndrome Pathogenic:4
Apr 20, 2023
Duke University Health System Sequencing Clinic, Duke University Health System
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Mar 29, 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

- -

Jan 17, 2023
Center of Genomic medicine, Geneva, University Hospital of Geneva
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The patient harbours this variant in an homozygous state, each copy being inherited form each parent -

-
Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

not provided Pathogenic:3
Dec 19, 2019
Clinical Genetics and Genomics, Karolinska University Hospital
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 01, 2018
CeGaT Center for Human Genetics Tuebingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 08, 2023
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 16826520, 31230720, 30868735, 34426522, 26752647) -

Peripheral neuropathy Pathogenic:1
Aug 22, 2016
Claritas Genomics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Lethal multiple pterygium syndrome Pathogenic:1
Nov 14, 2023
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.256C>T (p.Arg86Cys) results in a non-conservative amino acid change located in the neurotransmitter-gated ion-channel transmembrane domain (IPR006029) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 248786 control chromosomes (gnomAD). c.256C>T has been reported in the literature as a biallelic genotype in multiple individuals affected with Escobar Syndrome/Lethal Multiple Pterygium Syndrome - CHRNG Related (e.g. Hoffmann_2006, Bayram_2016, Pehlivan_2019). These data indicate that the variant is very likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 16826520, 26752647, 31230720). Six submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Autosomal recessive multiple pterygium syndrome;C1854678:Lethal multiple pterygium syndrome Pathogenic:1
Mar 21, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.91
BayesDel_addAF
Pathogenic
0.33
D
BayesDel_noAF
Pathogenic
0.41
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.82
D;.
Eigen
Uncertain
0.61
Eigen_PC
Uncertain
0.49
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Pathogenic
0.98
D;D
M_CAP
Pathogenic
0.43
D
MetaRNN
Pathogenic
0.98
D;D
MetaSVM
Uncertain
0.76
D
MutationAssessor
Pathogenic
3.5
M;M
PhyloP100
3.0
PrimateAI
Uncertain
0.78
T
PROVEAN
Pathogenic
-7.1
D;D
REVEL
Pathogenic
0.87
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0010
D;D
Polyphen
1.0
D;.
Vest4
0.90
MutPred
0.90
Loss of MoRF binding (P = 0.1005);Loss of MoRF binding (P = 0.1005);
MVP
0.88
MPC
0.69
ClinPred
0.94
D
GERP RS
4.0
Varity_R
0.89
Mutation Taster
=6/94
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs777219451; hg19: chr2-233405327; COSMIC: COSV99286158; COSMIC: COSV99286158; API