Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM2PM5BP4_Moderate
The NM_013335.4(GMPPA):c.1000A>G(p.Thr334Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T334P) has been classified as Pathogenic.
GMPPA (HGNC:22923): (GDP-mannose pyrophosphorylase A) This gene is thought to encode a GDP-mannose pyrophosphorylase. This enzyme catalyzes the reaction which converts mannose-1-phosphate and GTP to GDP-mannose which is involved in the production of N-linked oligosaccharides. [provided by RefSeq, Jul 2008]
Our verdict: Uncertain_significance. The variant received 2 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr2-219506260-A-C is described in ClinVar as Pathogenic. ClinVar VariationId is 88692.Status of the report is no_assertion_criteria_provided, 0 stars.
BP4
Computational evidence support a benign effect (MetaRNN=0.22954234).
Loss of catalytic residue at T334 (P = 0.0626);.;Loss of catalytic residue at T334 (P = 0.0626);Loss of catalytic residue at T334 (P = 0.0626);Loss of catalytic residue at T334 (P = 0.0626);Loss of catalytic residue at T334 (P = 0.0626);