Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate
The ENST00000284995.11(TSEN2):āc.911C>Gā(p.Ala304Gly) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000992 in 1,613,568 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (ā ).
TSEN2 (HGNC:28422): (tRNA splicing endonuclease subunit 2) This gene encodes one of the subunits of the tRNA splicing endonuclease. This endonuclease catalyzes the first step in RNA splicing which is the removal of introns. Mutations in this gene have been associated with pontocerebellar hypoplasia type 2. A pseudogene has been identified on chromosome 4. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Feb 2009]
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in ENST00000284995.11
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.871
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Dec 26, 2020
Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with TSEN2-related conditions. This variant is present in population databases (rs371023835, ExAC 0.02%). This sequence change replaces alanine with glycine at codon 304 of the TSEN2 protein (p.Ala304Gly). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and glycine. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -