6-1930219-C-T

Position:

• chr6-1930219-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001500.4(GMDS):​c.655G>A​(p.Val219Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000411 in 1,460,106 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 (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: GMDS NM_001500.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.57

Genes affected

GMDS (HGNC:4369): (GDP-mannose 4,6-dehydratase) GDP-mannose 4,6-dehydratase (GMD; EC 4.2.1.47) catalyzes the conversion of GDP-mannose to GDP-4-keto-6-deoxymannose, the first step in the synthesis of GDP-fucose from GDP-mannose, using NADP+ as a cofactor. The second and third steps of the pathway are catalyzed by a single enzyme, GDP-keto-6-deoxymannose 3,5-epimerase, 4-reductase, designated FX in humans (MIM 137020).[supplied by OMIM, Aug 2009]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.862

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GMDS	NM_001500.4	c.655G>A	p.Val219Ile	missense_variant	7/11	ENST00000380815.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GMDS	ENST00000380815.5	c.655G>A	p.Val219Ile	missense_variant	7/11	1	NM_001500.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1460106 Hom.: 0 Cov.: 29 AF XY: 0.00000551 AC XY: 4 AN XY: 726328

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 07, 2024

The c.655G>A (p.V219I) alteration is located in exon 7 (coding exon 7) of the GMDS gene. This alteration results from a G to A substitution at nucleotide position 655, causing the valine (V) at amino acid position 219 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.36
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.070
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.65	.;D
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D;D
M_CAP	Uncertain	0.28	D
MetaRNN	Pathogenic	0.86	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.8	.;H
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-1.0	N;N
REVEL	Pathogenic	0.80
Sift	Uncertain	0.019	D;D
Sift4G	Uncertain	0.014	D;D
Polyphen		1.0	.;D
Vest4		0.65
MutPred		0.81		.;Gain of methylation at K222 (P = 0.1015);
MVP		0.91
MPC		1.7
ClinPred		0.98	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.58
gMVP		0.56

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: rs1229471670; hg19: chr6-1930453;