Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate
The NM_024570.4(RNASEH2B):c.509dupA(p.Val171GlyfsTer2) variant causes a frameshift, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000414 in 1,449,854 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.
RNASEH2B (HGNC:25671): (ribonuclease H2 subunit B) RNase H2 is composed of a single catalytic subunit (A) and two non-catalytic subunits (B and C) and specifically degrades the RNA of RNA:DNA hybrids. The protein encoded by this gene is the non-catalytic B subunit of RNase H2, which is thought to play a role in DNA replication. Multiple transcript variants encoding different isoforms have been found for this gene. Defects in this gene are a cause of Aicardi-Goutieres syndrome type 2 (AGS2). [provided by RefSeq, Nov 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 13-50943386-G-GA is Pathogenic according to our data. Variant chr13-50943386-G-GA is described in ClinVar as [Pathogenic]. Clinvar id is 2820897.Status of the report is criteria_provided_single_submitter, 1 stars.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change creates a premature translational stop signal (p.Val171Glyfs*2) in the RNASEH2B gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in RNASEH2B are known to be pathogenic (PMID: 17846997). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with RNASEH2B-related conditions. For these reasons, this variant has been classified as Pathogenic. -