rs1555527149

Positions:

• chr17-2674287-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2 PP2 PP3_Strong PP5_Moderate

The NM_000430.4(PAFAH1B1):​c.899A>G​(p.Glu300Gly) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: PAFAH1B1 NM_000430.4 missense, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.32

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 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), PAFAH1B1. . Gene score misZ 3.5284 (greater than the threshold 3.09). Trascript score misZ 3.7057 (greater than threshold 3.09). GenCC has associacion of gene with lissencephaly due to LIS1 mutation.
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant 17-2674287-A-G is Pathogenic according to our data. Variant chr17-2674287-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 436140.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PAFAH1B1	NM_000430.4	c.899A>G	p.Glu300Gly	missense_variant, splice_region_variant	8/11	ENST00000397195.10	NP_000421.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PAFAH1B1	ENST00000397195.10	c.899A>G	p.Glu300Gly	missense_variant, splice_region_variant	8/11	1	NM_000430.4	ENSP00000380378	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Lissencephaly due to LIS1 mutation Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Jul 08, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.20	T;.
Eigen	Benign	-0.017
Eigen_PC	Benign	0.22
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;T
M_CAP	Benign	0.053	D
MetaRNN	Uncertain	0.54	D;T
MetaSVM	Benign	-0.61	T
MutationAssessor	Benign	0.090	N;.
MutationTaster	Benign	1.0	D;D;N
PrimateAI	Pathogenic	0.84	D
PROVEAN	Benign	-1.3	N;.
REVEL	Uncertain	0.42
Sift	Benign	0.13	T;.
Sift4G	Benign	0.19	T;T
Polyphen		0.021	B;.
Vest4		0.70
MutPred		0.39		Loss of sheet (P = 0.0228);.;
MVP		0.95
MPC		1.3
ClinPred		0.74	D
GERP RS		5.6
Varity_R		0.23
gMVP		0.86

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.16		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: rs1555527149; hg19: chr17-2577581;