Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate
The NM_003801.4(GPAA1):c.920delG(p.Gly307AlafsTer11) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.
GPAA1 (HGNC:4446): (glycosylphosphatidylinositol anchor attachment 1) Posttranslational glycosylphosphatidylinositol (GPI) anchor attachment serves as a general mechanism for linking proteins to the cell surface membrane. The protein encoded by this gene presumably functions in GPI anchoring at the GPI transfer step. The mRNA transcript is ubiquitously expressed in both fetal and adult tissues. The anchor attachment protein 1 contains an N-terminal signal sequence, 1 cAMP- and cGMP-dependent protein kinase phosphorylation site, 1 leucine zipper pattern, 2 potential N-glycosylation sites, and 8 putative transmembrane domains. [provided by RefSeq, Jul 2008]
Verdict is Pathogenic. Variant got 12 ACMG points.
PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 8-144084517-TG-T is Pathogenic according to our data. Variant chr8-144084517-TG-T is described in ClinVar as [Pathogenic]. Clinvar id is 453249.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr8-144084517-TG-T is described in Lovd as [Pathogenic].
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This premature translational stop signal has been observed in individual(s) with GPAA1-related conditions (PMID: 29100095). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gly307Alafs*11) in the GPAA1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GPAA1 are known to be pathogenic (PMID: 29100095). ClinVar contains an entry for this variant (Variation ID: 453249). For these reasons, this variant has been classified as Pathogenic. -