NM_000533.5:c.1_2delAT

Variant names:

• chrX-103776995-CAT-C
• NM_000533.5:c.1_2delAT

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000533.5(PLP1):​c.1_2delAT​(p.Met1fs) variant causes a frameshift, start lost, splice region change. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: PLP1 NM_000533.5 frameshift, start_lost, splice_region
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.55

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

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 52 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-103776995-CAT-C is Pathogenic according to our data. Variant chrX-103776995-CAT-C is described in ClinVar as [Pathogenic]. Clinvar id is 3723230.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PLP1	NM_000533.5	c.1_2delAT	p.Met1fs	frameshift_variant, start_lost, splice_region_variant	Exon 1 of 7	ENST00000621218.5	NP_000524.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PLP1	ENST00000621218.5	c.1_2delAT	p.Met1fs	frameshift_variant, start_lost, splice_region_variant	Exon 1 of 7	1	NM_000533.5	ENSP00000484450.1

Frequencies

GnomAD3 genomes Cov.: 23

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary spastic paraplegia 2 Pathogenic:1

Oct 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects the initiator methionine of the PLP1 mRNA. The next in-frame methionine is located at codon 206. This variant is not present in population databases (gnomAD no frequency). Disruption of the initiator codon has been observed in individuals with PLP1-related conditions (PMID: 8786077, 10417279, 12910435, 22343157). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chrX-103031923;