17-44911429-C-G

Variant names:

• chr17-44911429-C-G
• rs763868966
• NM_002055.5:c.934G>C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_002055.5(GFAP):​c.934G>C​(p.Glu312Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,610,918 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: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: GFAP NM_002055.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.13

Genes affected

GFAP (HGNC:4235): (glial fibrillary acidic protein) This gene encodes one of the major intermediate filament proteins of mature astrocytes. It is used as a marker to distinguish astrocytes from other glial cells during development. Mutations in this gene cause Alexander disease, a rare disorder of astrocytes in the central nervous system. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.81

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GFAP	NM_002055.5	c.934G>C	p.Glu312Gln	missense_variant	Exon 6 of 9	ENST00000588735.3	NP_002046.1
GFAP	NM_001363846.2	c.934G>C	p.Glu312Gln	missense_variant	Exon 6 of 10		NP_001350775.1
GFAP	NM_001242376.3	c.934G>C	p.Glu312Gln	missense_variant	Exon 6 of 7		NP_001229305.1
GFAP	NM_001131019.3	c.934G>C	p.Glu312Gln	missense_variant	Exon 6 of 8		NP_001124491.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GFAP	ENST00000588735.3	c.934G>C	p.Glu312Gln	missense_variant	Exon 6 of 9	1	NM_002055.5	ENSP00000466598.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152234 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1458684 Hom.: 0 Cov.: 33 AF XY: 0.00000276 AC XY: 2 AN XY: 725488

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152234 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74382

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Jul 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with glutamine, which is neutral and polar, at codon 312 of the GFAP protein (p.Glu312Gln). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with GFAP-related conditions. ClinVar contains an entry for this variant (Variation ID: 1941624). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on GFAP protein function. 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	Benign	0.23
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.050
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	.;D;.;.;.;.
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.81	D;D;D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Pathogenic	3.0	.;M;.;.;M;M
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-2.6	.;.;D;.;D;.
REVEL	Pathogenic	0.66
Sift	Uncertain	0.0010	.;.;D;.;D;.
Sift4G	Uncertain	0.0050	.;.;D;.;D;.
Polyphen		1.0	.;D;.;.;.;.
Vest4		0.48, 0.48
MutPred		0.73		Gain of MoRF binding (P = 0.0215);Gain of MoRF binding (P = 0.0215);Gain of MoRF binding (P = 0.0215);.;Gain of MoRF binding (P = 0.0215);Gain of MoRF binding (P = 0.0215);
MVP		0.99
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.81
gMVP		0.93

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs763868966; hg19: chr17-42988797;