17-44913325-A-C

Variant names:

• chr17-44913325-A-C
• rs60551555
• NM_002055.5:c.724T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_002055.5(GFAP):​c.724T>G​(p.Tyr242Asp) 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 not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y242C) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: GFAP NM_002055.5 missense
• Clinical Significance: not provided no classification provided O:2
• Conservation: PhyloP100: 7.52
• Publications: 9 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 8 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 12 uncertain in NM_002055.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GFAP	NM_002055.5	MANE Select	c.724T>G	p.Tyr242Asp	missense	Exon 4 of 9	NP_002046.1
	GFAP	NM_001363846.2		c.724T>G	p.Tyr242Asp	missense	Exon 4 of 10	NP_001350775.1
	GFAP	NM_001242376.3		c.724T>G	p.Tyr242Asp	missense	Exon 4 of 7	NP_001229305.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GFAP	ENST00000588735.3	TSL:1 MANE Select	c.724T>G	p.Tyr242Asp	missense	Exon 4 of 9	ENSP00000466598.2
	GFAP	ENST00000591327.2	TSL:1	n.1878T>G		non_coding_transcript_exon	Exon 2 of 5
	GFAP	ENST00000639277.1	TSL:5	c.724T>G	p.Tyr242Asp	missense	Exon 4 of 10	ENSP00000492432.1

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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	32
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.97	D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.7	H
PhyloP100		7.5
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-8.7	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.92		Gain of disorder (P = 0.0087)
MVP		1.0
MPC		1.6
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.97
gMVP		0.98
Mutation Taster		=0/100	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs60551555; hg19: chr17-42990693;