chr17-44915231-T-C

Variant names:

• chr17-44915231-T-C
• rs797044573
• NM_002055.5:c.256A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_002055.5(GFAP):​c.256A>G​(p.Lys86Glu) variant causes a missense change. 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. K86R) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GFAP NM_002055.5 missense
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 6.10
• Publications: 3 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_002055.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.922

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GFAP	NM_002055.5	c.256A>G	p.Lys86Glu	missense_variant	Exon 1 of 9	ENST00000588735.3	NP_002046.1
GFAP	NM_001363846.2	c.256A>G	p.Lys86Glu	missense_variant	Exon 1 of 10		NP_001350775.1
GFAP	NM_001242376.3	c.256A>G	p.Lys86Glu	missense_variant	Exon 1 of 7		NP_001229305.1
GFAP	NM_001131019.3	c.256A>G	p.Lys86Glu	missense_variant	Exon 1 of 8		NP_001124491.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GFAP	ENST00000588735.3	c.256A>G	p.Lys86Glu	missense_variant	Exon 1 of 9	1	NM_002055.5	ENSP00000466598.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: not provided

Submissions summary: Other:1

Revision: no classification provided

Submissions by phenotype

Alexander disease Other:1

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GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	.;D;.;.;.;D;.;.;.
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.45	D
MetaRNN	Pathogenic	0.92	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.5	.;H;.;H;H;.;.;.;.
PhyloP100		6.1
PrimateAI	Pathogenic	0.79	T
PROVEAN	Uncertain	-3.5	.;.;D;D;.;.;.;.;.
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0080	.;.;D;D;.;.;.;.;.
Sift4G	Uncertain	0.011	.;.;D;D;.;D;D;.;.
Polyphen		0.87	.;P;.;.;.;.;.;.;.
Vest4		0.86, 0.87, 0.88
MutPred		0.73		Loss of MoRF binding (P = 0.0075);Loss of MoRF binding (P = 0.0075);Loss of MoRF binding (P = 0.0075);Loss of MoRF binding (P = 0.0075);Loss of MoRF binding (P = 0.0075);Loss of MoRF binding (P = 0.0075);Loss of MoRF binding (P = 0.0075);Loss of MoRF binding (P = 0.0075);Loss of MoRF binding (P = 0.0075);
MVP		1.0
MPC		1.4
ClinPred		0.99	D
GERP RS		4.8
PromoterAI		-0.028	Neutral
Varity_R		0.84
gMVP		0.98
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: rs797044573; hg19: chr17-42992599;