Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2PP2PP3_Moderate
The NM_001130004.2(ACTN1):c.2255G>C(p.Arg752Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).
ACTN1 (HGNC:163): (actinin alpha 1) Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of cytoskeletal proteins, including the alpha and beta spectrins and dystrophins. Alpha actinin is an actin-binding protein with multiple roles in different cell types. In nonmuscle cells, the cytoskeletal isoform is found along microfilament bundles and adherens-type junctions, where it is involved in binding actin to the membrane. In contrast, skeletal, cardiac, and smooth muscle isoforms are localized to the Z-disc and analogous dense bodies, where they help anchor the myofibrillar actin filaments. This gene encodes a nonmuscle, cytoskeletal, alpha actinin isoform and maps to the same site as the structurally similar erythroid beta spectrin gene. Three transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]
Verdict is Uncertain_significance. Variant got 5 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the ACTN1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 22 curated pathogenic missense variants (we use a threshold of 10). The gene has 8 curated benign missense variants. Gene score misZ: 3.3621 (above the threshold of 3.09). Trascript score misZ: 5.1933 (above the threshold of 3.09). GenCC associations: The gene is linked to autosomal dominant macrothrombocytopenia, platelet-type bleeding disorder 15.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.899
Gain of catalytic residue at N756 (P = 0.0833);Gain of catalytic residue at N756 (P = 0.0833);Gain of catalytic residue at N756 (P = 0.0833);.;Gain of catalytic residue at N756 (P = 0.0833);.;