Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM2PM5PP3_StrongPP5_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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E300D) has been classified as Likely pathogenic.
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]
Our verdict: Pathogenic. The variant received 10 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr17-2674288-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 436141.Status of the report is criteria_provided_single_submitter, 1 stars.
PP3
Splicing predictors support a deleterious 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 VariationId is 436140.Status of the report is criteria_provided_single_submitter, 1 stars.