X-103787904-T-G

Position:

• chrX-103787904-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000533.5(PLP1):​c.560T>G​(p.Ile187Ser) 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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: PLP1 NM_000533.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.67

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]

PLP1 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a chain Myelin proteolipid protein (size 275) in uniprot entity MYPR_HUMAN there are 52 pathogenic changes around while only 0 benign (100%) in NM_000533.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.973

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PLP1	NM_000533.5	c.560T>G	p.Ile187Ser	missense_variant	4/7	ENST00000621218.5	NP_000524.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PLP1	ENST00000621218.5	c.560T>G	p.Ile187Ser	missense_variant	4/7	1	NM_000533.5	ENSP00000484450.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary spastic paraplegia 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 22, 2019

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant disrupts the p.Ile187 (also known as p.Ile186) amino acid residue in PLP1. Other variant(s) that disrupt this residue have been observed in individuals with PLP1-related conditions (PMID: 7522741, 23344956, 24139698), suggesting that it is a clinically significant residue. As a result, variants that disrupt this residue are likely to be causative of disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with PLP1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces isoleucine with serine at codon 187 of the PLP1 protein (p.Ile187Ser). The isoleucine residue is highly conserved and there is a large physicochemical difference between isoleucine and serine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	D;D;.
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D;.;D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.97	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	2.0	M;M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.61	T
Sift4G	Uncertain	0.0060	D;D;D
Polyphen		0.98	D;D;P
Vest4		0.73
MutPred		0.83		Gain of disorder (P = 3e-04);Gain of disorder (P = 3e-04);.;
MVP		0.99
ClinPred		0.98	D
GERP RS		5.6
Varity_R		0.85
gMVP		0.98

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

LitVar

Other links and lift over

dbSNP: rs132630288; hg19: chrX-103042833;