8-74364270-G-A

Position:

• chr8-74364270-G-A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM2 PP3 PP5_Very_Strong

The NM_018972.4(GDAP1):​c.980G>A​(p.Gly327Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,880 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 (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: GDAP1 NM_018972.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3 U:1
• Conservation: PhyloP100: 9.36

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]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.824
• PP5: Variant 8-74364270-G-A is Pathogenic according to our data. Variant chr8-74364270-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 40049.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr8-74364270-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GDAP1	NM_018972.4	c.980G>A	p.Gly327Asp	missense_variant	6/6	ENST00000220822.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GDAP1	ENST00000220822.12	c.980G>A	p.Gly327Asp	missense_variant	6/6	1	NM_018972.4	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461880 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727244

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Charcot-Marie-Tooth disease recessive intermediate A Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

May 01, 2011

- -

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

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 17, 2023

This sequence change replaces glycine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 327 of the GDAP1 protein (p.Gly327Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with autosomal recessive Charcot-Marie-Tooth disease (PMID: 21365284, 32376792; Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 40049). 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. Experimental studies have shown that this missense change affects GDAP1 function (PMID: 21365284, 33477664). For these reasons, this variant has been classified as Pathogenic. -

Charcot-Marie-Tooth disease, axonal, with vocal cord paresis, autosomal recessive Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

3billion

Feb 23, 2023

The variant is not observed in the gnomAD v2.1.1 dataset. Functional studies provide strong evidence of the variant having a damaging effect on the gene or gene product (PMID: 21365284). In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.83; 3Cnet: 0.73). Same nucleotide change resulting in same amino acid change has been previously reported to be associated with GDAP1-related disorder (ClinVar ID: VCV000040049 / PMID: 21365284). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -

Charcot-Marie-Tooth disease axonal type 2K Uncertain:1

Uncertain significance, no assertion criteria provided

literature only

Inherited Neuropathy Consortium Ii, University Of Miami

Jan 06, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Benign	0.26	T;.
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.88	D;D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.82	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	0.97	L;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.75	T
PROVEAN	Benign	-1.4	N;N
REVEL	Pathogenic	0.83
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.0040	D;D
Polyphen		0.99	D;.
Vest4		0.90
MutPred		0.53		Gain of loop (P = 0.0502);.;
MVP		0.99
MPC		0.97
ClinPred		0.88	D
GERP RS		5.0
Varity_R		0.58
gMVP		0.95

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

LitVar

Other links and lift over

dbSNP: rs397515432; hg19: chr8-75276505;