chr17-2672761-A-G

Variant names:

• chr17-2672761-A-G
• rs587784279
• NM_000430.4:c.671+4A>G

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM2 PP5_Moderate BP4

The NM_000430.4(PAFAH1B1):​c.671+4A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PAFAH1B1 NM_000430.4 splice_region, intron
• Scores: Splicing: ADA: 0.7984
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.884
• Publications: 1 publications found

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]

PAFAH1B1 Gene-Disease associations (from GenCC):

• lissencephaly due to LIS1 mutation

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-2672761-A-G is Pathogenic according to our data. Variant chr17-2672761-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 159536.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.35). . Strength limited to SUPPORTING due to the PP5.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000430.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PAFAH1B1	NM_000430.4	MANE Select	c.671+4A>G		splice_region intron	N/A	NP_000421.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PAFAH1B1	ENST00000397195.10	TSL:1 MANE Select	c.671+4A>G		splice_region intron	N/A	ENSP00000380378.4
	PAFAH1B1	ENST00000572915.6	TSL:1	n.639+4A>G		splice_region intron	N/A
	PAFAH1B1	ENST00000571495.2	TSL:2	n.458A>G		non_coding_transcript_exon	Exon 1 of 4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 24

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Likely pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Lissencephaly due to LIS1 mutation (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.35
CADD	Benign	21
DANN	Benign	0.91
PhyloP100		0.88

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.80
dbscSNV1_RF	Benign	0.53
SpliceAI score (max)		0.72		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.72		Position offset: -4

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs587784279; hg19: chr17-2576055;