chr17-44915228-C-G

Variant names:

• chr17-44915228-C-G
• rs267607518
• NM_002055.5:c.259G>C

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1 PM2 PM5 PP3_Moderate PP5_Very_Strong

The NM_002055.5(GFAP):​c.259G>C​(p.Val87Leu) variant causes a missense change involving the alteration of a 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V87F) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GFAP NM_002055.5 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2 O:2
• Conservation: PhyloP100: 7.73
• Publications: 4 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: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen, G2P
• Alexander disease type II

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 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 chr17-44915228-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1351005.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.938
• PP5: Variant 17-44915228-C-G is Pathogenic according to our data. Variant chr17-44915228-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 66477.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002055.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GFAP	NM_002055.5	MANE Select	c.259G>C	p.Val87Leu	missense	Exon 1 of 9	NP_002046.1	P14136-1
	GFAP	NM_001363846.2		c.259G>C	p.Val87Leu	missense	Exon 1 of 10	NP_001350775.1	A0A1X7SBR3
	GFAP	NM_001242376.3		c.259G>C	p.Val87Leu	missense	Exon 1 of 7	NP_001229305.1	P14136-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GFAP	ENST00000588735.3	TSL:1 MANE Select	c.259G>C	p.Val87Leu	missense	Exon 1 of 9	ENSP00000466598.2	P14136-1
	GFAP	ENST00000591327.2	TSL:1	n.272G>C		non_coding_transcript_exon	Exon 1 of 5
	GFAP	ENST00000639277.1	TSL:5	c.259G>C	p.Val87Leu	missense	Exon 1 of 10	ENSP00000492432.1	A0A1W2PR46

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	Alexander disease (3)
-	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.46	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	H
PhyloP100		7.7
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-2.6	D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		0.67	P
Vest4		0.96
MutPred		0.80		Loss of methylation at K86 (P = 0.0363)
MVP		1.0
MPC		0.93
ClinPred		1.0	D
GERP RS		3.7
PromoterAI		-0.017	Neutral
Varity_R		0.91
gMVP		0.97
Mutation Taster		=2/98	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: rs267607518; hg19: chr17-42992596;