rs771588131

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM2PP3_Strong

The NM_005199.5(CHRNG):​c.250G>A​(p.Asp84Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,611,728 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

CHRNG
NM_005199.5 missense

Scores

7
11
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 8.39

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: Likely_pathogenic. The variant received 8 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_005199.5
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.983

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNGNM_005199.5 linkc.250G>A p.Asp84Asn 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.250G>A p.Asp84Asn missense_variant Exon 4 of 12 NM_005199.5 ENSP00000498757.1 P07510-1
CHRNGENST00000389492.3 linkc.250G>A p.Asp84Asn missense_variant Exon 4 of 11 1 ENSP00000374143.3 P07510-2
CHRNGENST00000485094.1 linkn.271G>A non_coding_transcript_exon_variant Exon 4 of 5 1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152182
Hom.:
0
Cov.:
33
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:
0.00000806
AC:
2
AN:
248228
AF XY:
0.0000149
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:
0.00
Gnomad NFE exome
AF:
0.0000177
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000548
AC:
8
AN:
1459546
Hom.:
0
Cov.:
32
AF XY:
0.00000688
AC XY:
5
AN XY:
726218
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.00
AC:
0
AN:
44674
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86210
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51480
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5698
European-Non Finnish (NFE)
AF:
0.00000720
AC:
8
AN:
1111858
Other (OTH)
AF:
0.00
AC:
0
AN:
60348
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.444
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

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:
152182
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74338
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41442
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive multiple pterygium syndrome Uncertain:3
Oct 28, 2019
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was classified as: Uncertain significance. The available evidence favors the pathogenic nature of this variant, however the currently available data is insufficient to conclusively support its pathogenic nature. Thus this variant is classified as Uncertain significance - favor pathogenic. The following ACMG criteria were applied in classifying this variant: PM2,PM3,PP3. -

Jan 04, 2016
Molecular Diagnostics Lab, Nemours Children's Health, Delaware
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Lethal multiple pterygium syndrome Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.95
BayesDel_addAF
Pathogenic
0.17
D
BayesDel_noAF
Uncertain
0.030
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.76
D;.
Eigen
Uncertain
0.53
Eigen_PC
Uncertain
0.43
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.97
D;D
M_CAP
Pathogenic
0.43
D
MetaRNN
Pathogenic
0.98
D;D
MetaSVM
Pathogenic
0.94
D
MutationAssessor
Uncertain
2.2
M;M
PhyloP100
8.4
PrimateAI
Uncertain
0.66
T
PROVEAN
Pathogenic
-4.4
D;D
REVEL
Uncertain
0.60
Sift
Uncertain
0.0020
D;D
Sift4G
Uncertain
0.0060
D;D
Polyphen
1.0
D;.
Vest4
0.93
MutPred
0.90
Gain of MoRF binding (P = 0.0412);Gain of MoRF binding (P = 0.0412);
MVP
0.92
MPC
0.57
ClinPred
0.98
D
GERP RS
3.2
Varity_R
0.76
Mutation Taster
=86/14
polymorphism

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: rs771588131; hg19: chr2-233405321; API