chrX-103786493-G-A

Variant names:

• chrX-103786493-G-A
• rs132630285
• NM_000533.5:c.220G>A

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000533.5(PLP1):​c.220G>A​(p.Gly74Arg) 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G74E) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 22)
• Consequence: PLP1 NM_000533.5 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 9.60
• Publications: 6 publications found

Genes affected

PLP1 (HGNC:9086): (proteolipid protein 1) This gene encodes a transmembrane proteolipid protein that is the predominant component of myelin. The encoded protein may play a role in the compaction, stabilization, and maintenance of myelin sheaths, as well as in oligodendrocyte development and axonal survival. Mutations in this gene cause Pelizaeus-Merzbacher disease and spastic paraplegia type 2. Alternatively splicing results in multiple transcript variants, including the DM20 splice variant. [provided by RefSeq, Feb 2015]

ENSG00000288597 (HGNC:):

RAB9B (HGNC:14090): (RAB9B, member RAS oncogene family) This gene encodes a member of a subfamily of RAS small guanosine triphosphate (GTP)-binding proteins that regulate membrane trafficking. The encoded protein may be involved in endosome-to-Golgi transport. [provided by RefSeq, Jan 2010]

ACMG classification

Our verdict: Pathogenic. The variant received 12 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, 8 uncertain in NM_000533.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrX-103786494-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 3255410.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 40 curated pathogenic missense variants (we use a threshold of 10). The gene has 4 curated benign missense variants. Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to hereditary spastic paraplegia 2, Pelizeaus-Merzbacher spectrum disorder, Pelizaeus-Merzbacher disease in female carriers, null syndrome, Pelizaeus-Merzbacher disease, transitional form, Pelizaeus-Merzbacher disease, classic form, Pelizaeus-Merzbacher disease, connatal form.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant X-103786493-G-A is Pathogenic according to our data. Variant chrX-103786493-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 11082.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000533.5. 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
	PLP1	NM_000533.5	MANE Select	c.220G>A	p.Gly74Arg	missense	Exon 3 of 7	NP_000524.3
	PLP1	NM_001128834.3		c.220G>A	p.Gly74Arg	missense	Exon 4 of 8	NP_001122306.1
	PLP1	NM_199478.3		c.220G>A	p.Gly74Arg	missense	Exon 3 of 7	NP_955772.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PLP1	ENST00000621218.5	TSL:1 MANE Select	c.220G>A	p.Gly74Arg	missense	Exon 3 of 7	ENSP00000484450.1
	PLP1	ENST00000619236.1	TSL:1	c.220G>A	p.Gly74Arg	missense	Exon 3 of 7	ENSP00000477619.1
	PLP1	ENST00000612423.4	TSL:2	c.220G>A	p.Gly74Arg	missense	Exon 4 of 8	ENSP00000481006.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 22

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Pelizaeus-Merzbacher disease Pathogenic:1

Jul 01, 1992

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.71	D
BayesDel_noAF	Pathogenic	0.78
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.79	D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.7	M
PhyloP100		9.6
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-7.2	D
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0040	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.96		Gain of catalytic residue at G74 (P = 0.059)
MVP		1.0
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.94
gMVP		0.99
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs132630285; hg19: chrX-103041422;