NM_002055.5:c.773G>C

Variant names:

• chr17-44913276-C-G
• rs61726468
• NM_002055.5:c.773G>C

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_002055.5(GFAP):​c.773G>C​(p.Arg258Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R258C) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: GFAP NM_002055.5 missense
• Clinical Significance: not provided no classification provided O:2
• Conservation: PhyloP100: 2.90
• Publications: 6 publications found

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]

GFAP Gene-Disease associations (from GenCC):

• Alexander disease

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
• Alexander disease type II

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_002055.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-44913277-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 190345.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.976

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GFAP	NM_002055.5	c.773G>C	p.Arg258Pro	missense_variant	Exon 4 of 9	ENST00000588735.3	NP_002046.1
GFAP	NM_001363846.2	c.773G>C	p.Arg258Pro	missense_variant	Exon 4 of 10		NP_001350775.1
GFAP	NM_001242376.3	c.773G>C	p.Arg258Pro	missense_variant	Exon 4 of 7		NP_001229305.1
GFAP	NM_001131019.3	c.773G>C	p.Arg258Pro	missense_variant	Exon 4 of 8		NP_001124491.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GFAP	ENST00000588735.3	c.773G>C	p.Arg258Pro	missense_variant	Exon 4 of 9	1	NM_002055.5	ENSP00000466598.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: not provided

Submissions summary: Other:2

Revision: no classification provided

Submissions by phenotype

not provided Other:1

-

Epithelial Biology; Institute of Medical Biology, Singapore

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Alexander disease Other:1

-

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.86	.;D;.;.;.;.;.;D;.
Eigen	Uncertain	0.57
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.38	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.5	.;M;.;.;M;M;.;.;.
PhyloP100		2.9
PrimateAI	Uncertain	0.52	T
PROVEAN	Uncertain	-3.2	.;.;D;.;D;.;.;.;.
REVEL	Pathogenic	0.78
Sift	Pathogenic	0.0	.;.;D;.;D;.;.;.;.
Sift4G	Uncertain	0.0020	.;.;D;.;D;.;D;.;.
Polyphen		0.99	.;D;.;.;.;.;.;.;.
Vest4		0.88, 0.89, 0.92
MutPred		0.91		Loss of MoRF binding (P = 0.049);Loss of MoRF binding (P = 0.049);Loss of MoRF binding (P = 0.049);.;Loss of MoRF binding (P = 0.049);Loss of MoRF binding (P = 0.049);Loss of MoRF binding (P = 0.049);.;.;
MVP		1.0
MPC		1.4
ClinPred		0.99	D
GERP RS		5.1
Varity_R		0.96
gMVP		0.99
Mutation Taster		=8/92	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs61726468; hg19: chr17-42990644;