rs1556268920

Positions:

• chrX-103787829-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 6P and 1B. PM1 PM2 PM5 BP4

The NM_000533.5(PLP1):​c.485T>C​(p.Val162Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V162E) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 22)
• Consequence: PLP1 NM_000533.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.66

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]

RAB9B (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 5 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, 3 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 chrnull-null-null-null is described in UniProt as null.
• BP4: Computational evidence support a benign effect (MetaRNN=0.40967083).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PLP1	NM_000533.5	c.485T>C	p.Val162Ala	missense_variant	4/7	ENST00000621218.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PLP1	ENST00000621218.5	c.485T>C	p.Val162Ala	missense_variant	4/7	1	NM_000533.5	P1

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

Invitae

Dec 11, 2017

This sequence change replaces valine with alanine at codon 162 of the PLP1 protein (p.Val162Ala). The valine residue is moderately conserved and there is a small physicochemical difference between valine and alanine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with PLP1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C25"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Benign	-0.053	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	20
DANN	Benign	0.59
DEOGEN2	Uncertain	0.76	D;D;.
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Benign	0.75	T;.;T
M_CAP	Pathogenic	0.56	D
MetaRNN	Benign	0.41	T;T;T
MetaSVM	Uncertain	0.79	D
MutationAssessor	Benign	-0.69	N;N;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.57	T
Sift4G	Benign	0.12	T;T;T
Polyphen		0.081	B;B;B
Vest4		0.14
MutPred		0.53		Loss of stability (P = 0.1576);Loss of stability (P = 0.1576);.;
MVP		0.64
ClinPred		0.30	T
GERP RS		5.7
Varity_R		0.12
gMVP		0.87

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: rs1556268920; hg19: chrX-103042758;