8-74350570-T-A

Position:

• chr8-74350570-T-A

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_018972.4(GDAP1):​c.109T>A​(p.Ser37Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000488 in 1,434,190 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000049 (0 hom.)
• Consequence: GDAP1 NM_018972.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2
• Conservation: PhyloP100: 7.31

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a domain GST N-terminal (size 81) in uniprot entity GDAP1_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_018972.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.939
• PP5: Variant 8-74350570-T-A is Pathogenic according to our data. Variant chr8-74350570-T-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 426898.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GDAP1	NM_018972.4	c.109T>A	p.Ser37Thr	missense_variant	1/6	ENST00000220822.12	NP_061845.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GDAP1	ENST00000220822.12	c.109T>A	p.Ser37Thr	missense_variant	1/6	1	NM_018972.4	ENSP00000220822.7

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251336 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135874

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000488 AC: 7 AN: 1434190 Hom.: 0 Cov.: 27 AF XY: 0.00000140 AC XY: 1 AN XY: 715138

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: 0.00000644

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

Alfa AF: 0.0000508 Hom.: 0

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.0000545

EpiControl AF: 0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Mar 28, 2017

A variant that is likely pathogenic has been identified in the GDAP1 gene. The S37T variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The S37T variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). This substitution occurs at a conserved position predicted to be within the GST N-terminal domain. Missense variants at other residues in the GST domain have been reported in Human Gene Mutation Database in association with GDAP1-related disorders (Stenson et al., 2014), supporting the functional importance of this region of the protein. However, the S37T variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Therefore, this variant is likely pathogenic; however, the possibility that it is benign cannot be excluded. -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 07, 2017

- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 30, 2023

This sequence change replaces serine, which is neutral and polar, with threonine, which is neutral and polar, at codon 37 of the GDAP1 protein (p.Ser37Thr). This variant is present in population databases (rs756121249, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with GDAP1-related conditions. ClinVar contains an entry for this variant (Variation ID: 426898). 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Benign	0.13	T
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Benign	0.59	D
LIST_S2	Uncertain	0.92	D
M_CAP	Benign	0.047	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Benign	-0.84	T
MutationAssessor	Uncertain	2.9	M
PrimateAI	Uncertain	0.75	T
PROVEAN	Benign	-1.8	N
REVEL	Uncertain	0.44
Sift	Uncertain	0.012	D
Sift4G	Uncertain	0.026	D
Polyphen		0.99	D
Vest4		0.85
MutPred		0.85		Loss of MoRF binding (P = 0.1316);
MVP		0.73
MPC		1.1
ClinPred		0.98	D
GERP RS		5.1
Varity_R		0.74
gMVP		0.91

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: rs756121249; hg19: chr8-75262805;