rs587784254

Variant names:

• chr17-2666061-T-A
• rs587784254
• NM_000430.4:c.163T>A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP2 PP3_Moderate PP5

The NM_000430.4(PAFAH1B1):​c.163T>A​(p.Trp55Arg) 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 Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PAFAH1B1 NM_000430.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 7.55

Genes affected

PAFAH1B1 (HGNC:8574): (platelet activating factor acetylhydrolase 1b regulatory subunit 1) This locus was identified as encoding a gene that when mutated or lost caused the lissencephaly associated with Miller-Dieker lissencephaly syndrome. This gene encodes the non-catalytic alpha subunit of the intracellular Ib isoform of platelet-activating factor acteylhydrolase, a heterotrimeric enzyme that specifically catalyzes the removal of the acetyl group at the SN-2 position of platelet-activating factor (identified as 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine). Two other isoforms of intracellular platelet-activating factor acetylhydrolase exist: one composed of multiple subunits, the other, a single subunit. In addition, a single-subunit isoform of this enzyme is found in serum. [provided by RefSeq, Apr 2009]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the PAFAH1B1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 39 curated pathogenic missense variants (we use a threshold of 10). The gene has 16 curated benign missense variants. Gene score misZ: 3.5284 (above the threshold of 3.09). Trascript score misZ: 3.7057 (above the threshold of 3.09). GenCC associations: The gene is linked to lissencephaly due to LIS1 mutation.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.912
• PP5: Variant 17-2666061-T-A is Pathogenic according to our data. Variant chr17-2666061-T-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 159507.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PAFAH1B1	NM_000430.4	c.163T>A	p.Trp55Arg	missense_variant	Exon 4 of 11	ENST00000397195.10	NP_000421.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAFAH1B1	ENST00000397195.10	c.163T>A	p.Trp55Arg	missense_variant	Exon 4 of 11	1	NM_000430.4	ENSP00000380378.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Inborn genetic diseases Pathogenic:1

Dec 21, 2017

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Lissencephaly due to LIS1 mutation Pathogenic:1

Feb 08, 2013

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Uncertain:1

Oct 03, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 10583396) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.50	D;D
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D;D
M_CAP	Pathogenic	0.43	D
MetaRNN	Pathogenic	0.91	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.9	.;H
PrimateAI	Pathogenic	0.95	D
PROVEAN	Pathogenic	-14	.;D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	.;D
Sift4G	Uncertain	0.0030	D;D
Polyphen		1.0	.;D
Vest4		0.89
MutPred		0.64		Gain of disorder (P = 6e-04);Gain of disorder (P = 6e-04);
MVP		0.91
MPC		3.0
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.95
gMVP		0.96

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: rs587784254; hg19: chr17-2569355;