17-2638320-T-C

Variant names:

• chr17-2638320-T-C
• NM_000430.4:c.32T>C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Strong

The NM_000430.4(PAFAH1B1):​c.32T>C​(p.Leu11Pro) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PAFAH1B1 NM_000430.4 missense, splice_region
• Scores: Splicing: ADA: 0.04762
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.76

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 7 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, 0.973

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PAFAH1B1	NM_000430.4	c.32T>C	p.Leu11Pro	missense_variant, splice_region_variant	Exon 2 of 11	ENST00000397195.10	NP_000421.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAFAH1B1	ENST00000397195.10	c.32T>C	p.Leu11Pro	missense_variant, splice_region_variant	Exon 2 of 11	1	NM_000430.4	ENSP00000380378.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Feb 21, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 11 of the PAFAH1B1 protein (p.Leu11Pro). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PAFAH1B1-related conditions. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	32
DANN	Benign	0.96
DEOGEN2	Pathogenic	0.81	D;D
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.91	D;D
M_CAP	Pathogenic	0.41	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Pathogenic	0.81	D
MutationAssessor	Pathogenic	3.4	.;M
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-6.3	.;D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	.;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		0.99	.;D
Vest4		0.82
MutPred		0.89		Loss of stability (P = 0.0152);Loss of stability (P = 0.0152);
MVP		0.95
MPC		2.8
ClinPred		0.99	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.87

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.048
dbscSNV1_RF	Benign	0.35
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: chr17-2541614;