rs368055667

Variant names:

• chr8-74364197-G-A
• rs368055667
• NM_018972.4:c.907G>A

Your query was ambiguous. Multiple possible variants found:

• chr8-74364197-G-A
• chr8-74364197-G-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_018972.4(GDAP1):​c.907G>A​(p.Ala303Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,846 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A303V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GDAP1 NM_018972.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.36
• Publications: 0 publications found

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.789

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GDAP1	NM_018972.4	c.907G>A	p.Ala303Thr	missense_variant	Exon 6 of 6	ENST00000220822.12	NP_061845.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GDAP1	ENST00000220822.12	c.907G>A	p.Ala303Thr	missense_variant	Exon 6 of 6	1	NM_018972.4	ENSP00000220822.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461846 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727232

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 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: 1111972

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Charcot-Marie-Tooth disease type 4A Uncertain:1

Sep 10, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 1299124). This variant has not been reported in the literature in individuals affected with GDAP1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 303 of the GDAP1 protein (p.Ala303Thr). -

not provided Uncertain:1

Feb 01, 2022

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.81
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.13	T;.
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.79	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.0	M;.
PhyloP100		9.4
PrimateAI	Pathogenic	0.82	D
PROVEAN	Benign	-0.47	N;N
REVEL	Pathogenic	0.68
Sift	Uncertain	0.011	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.70
MutPred		0.46		Gain of glycosylation at A303 (P = 0.045);.;
MVP		0.99
MPC		1.3
ClinPred		0.87	D
GERP RS		5.0
Varity_R		0.22
gMVP		0.86
Mutation Taster		=30/70	disease causing

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

Other links and lift over

dbSNP: rs368055667; hg19: chr8-75276432;