8-74364066-A-G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1PM2PP2BP4

The NM_018972.4(GDAP1):​c.776A>G​(p.Lys259Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,614,022 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

GDAP1
NM_018972.4 missense

Scores

2
6
11

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.03

Publications

2 publications found
Variant links:
Genes affected
GDAP1 (HGNC:15968): (ganglioside induced differentiation associated protein 1) This gene encodes a member of the ganglioside-induced differentiation-associated protein family, which may play a role in a signal transduction pathway during neuronal development. Mutations in this gene have been associated with various forms of Charcot-Marie-Tooth Disease and neuropathy. Two transcript variants encoding different isoforms and a noncoding variant have been identified for this gene. [provided by RefSeq, Feb 2012]
GDAP1 Gene-Disease associations (from GenCC):
  • Charcot-Marie-Tooth disease
    Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
  • Charcot-Marie-Tooth disease axonal type 2K
    Inheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
  • Charcot-Marie-Tooth disease recessive intermediate A
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
  • autosomal dominant Charcot-Marie-Tooth disease type 2K
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Charcot-Marie-Tooth disease type 4A
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 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_018972.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 32 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 1.0 (below the threshold of 3.09). Trascript score misZ: 1.1646 (below the threshold of 3.09). GenCC associations: The gene is linked to Charcot-Marie-Tooth disease axonal type 2K, Charcot-Marie-Tooth disease recessive intermediate A, Charcot-Marie-Tooth disease type 4A, Charcot-Marie-Tooth disease, autosomal dominant Charcot-Marie-Tooth disease type 2K.
BP4
Computational evidence support a benign effect (MetaRNN=0.30665818).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GDAP1NM_018972.4 linkc.776A>G p.Lys259Arg missense_variant Exon 6 of 6 ENST00000220822.12 NP_061845.2 Q8TB36-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GDAP1ENST00000220822.12 linkc.776A>G p.Lys259Arg missense_variant Exon 6 of 6 1 NM_018972.4 ENSP00000220822.7 Q8TB36-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152166
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:
0.00000398
AC:
1
AN:
251470
AF XY:
0.00000736
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:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461856
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727224
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
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:
0.00000180
AC:
2
AN:
1111974
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152166
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74350
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41430
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:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
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:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease recessive intermediate A Uncertain:1
Jan 12, 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. -

Charcot-Marie-Tooth disease type 4A Uncertain:1
Jan 08, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces lysine with arginine at codon 259 of the GDAP1 protein (p.Lys259Arg). The lysine residue is highly conserved and there is a small physicochemical difference between lysine and arginine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with GDAP1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Charcot-Marie-Tooth disease, axonal, with vocal cord paresis, autosomal recessive Uncertain:1
Jan 12, 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
Benign
0.095
BayesDel_addAF
Pathogenic
0.18
D
BayesDel_noAF
Uncertain
0.020
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.26
T;.
Eigen
Benign
-0.091
Eigen_PC
Benign
0.12
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.89
D;D
M_CAP
Benign
0.041
D
MetaRNN
Benign
0.31
T;T
MetaSVM
Uncertain
0.45
D
MutationAssessor
Benign
1.3
L;.
PhyloP100
7.0
PrimateAI
Uncertain
0.64
T
PROVEAN
Benign
-0.82
N;N
REVEL
Uncertain
0.51
Sift
Benign
0.20
T;T
Sift4G
Benign
0.094
T;T
Polyphen
0.049
B;.
Vest4
0.30
MutPred
0.63
Loss of catalytic residue at K259 (P = 0.0645);.;
MVP
0.96
MPC
0.39
ClinPred
0.57
D
GERP RS
5.0
Varity_R
0.26
gMVP
0.64
Mutation Taster
=87/13
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: rs778557691; hg19: chr8-75276301; API