NM_018972.4:c.1A>G

Variant names:

• chr8-74350462-A-G
• rs1474390668
• NM_018972.4:c.1A>G

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_018972.4(GDAP1):​c.1A>G​(p.Met1?) variant causes a start lost change. The variant allele was found at a frequency of 0.00000138 in 1,449,192 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 Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GDAP1 NM_018972.4 start_lost
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 3.60

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 14 ACMG points.

• PVS1: Start lost variant, next in-frame start position is after 6 pathogenic variants. Next in-frame start position is after 69 codons. Genomic position: 74351361. Lost 0.190 part of the original CDS.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-74350462-A-G is Pathogenic according to our data. Variant chr8-74350462-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 2423924.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GDAP1	NM_018972.4	c.1A>G	p.Met1?	start_lost	Exon 1 of 6	ENST00000220822.12	NP_061845.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GDAP1	ENST00000220822.12	c.1A>G	p.Met1?	start_lost	Exon 1 of 6	1	NM_018972.4	ENSP00000220822.7

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD3 exomes AF: 0.00000803 AC: 2 AN: 249032 Hom.: 0 AF XY: 0.00000741 AC XY: 1 AN XY: 134890

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: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000885

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1449192 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 721832

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000167

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Sep 08, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is present in population databases (no rsID available, gnomAD 0.003%). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 2423924). Disruption of the initiator codon has been observed in individuals with autosomal recessive Charcot-Marie-Tooth disease (PMID: 29184355, 33179230). It has also been observed to segregate with disease in related individuals. This sequence change affects the initiator methionine of the GDAP1 mRNA. The next in-frame methionine is located at codon 69. -

Charcot-Marie-Tooth disease recessive intermediate A;C1842983:Charcot-Marie-Tooth disease axonal type 2K;C1843183:Charcot-Marie-Tooth disease, axonal, with vocal cord paresis, autosomal recessive;C1859198:Charcot-Marie-Tooth disease type 4A Pathogenic:1

Apr 10, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.46
CADD	Benign	21
DANN	Uncertain	0.99
DEOGEN2	Benign	0.10	T
Eigen	Benign	-0.30
Eigen_PC	Benign	-0.21
FATHMM_MKL	Benign	0.18	N
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	0.74	D
PROVEAN	Benign	-0.23	N
REVEL	Uncertain	0.60
Sift	Pathogenic	0.0	D
Sift4G	Benign	0.068	T
Polyphen		0.0070	B
Vest4		0.62
MutPred		0.99		Gain of loop (P = 0.0851);
MVP		0.93
ClinPred		0.99	D
GERP RS		3.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6
Varity_R		0.94
gMVP		0.48

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: rs1474390668; hg19: chr8-75262697;