2-3548002-C-T

Position:

• chr2-3548002-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_002936.6(RNASEH1):​c.703G>A​(p.Gly235Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,576 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. G235G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: RNASEH1 NM_002936.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.33

Genes affected

RNASEH1 (HGNC:18466): (ribonuclease H1) This gene encodes an endonuclease that specifically degrades the RNA of RNA-DNA hybrids and plays a key role in DNA replication and repair. Alternate in-frame start codon initiation results in the production of alternate isoforms that are directed to the mitochondria or to the nucleus. The production of the mitochondrial isoform is modulated by an upstream open reading frame (uORF). Mutations in this gene have been found in individuals with progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 2. Alternative splicing results in additional coding and non-coding transcript variants. Pseudogenes of this gene have been defined on chromosomes 2 and 17. [provided by RefSeq, Jul 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a domain RNase H type-1 (size 146) in uniprot entity RNH1_HUMAN there are 4 pathogenic changes around while only 1 benign (80%) in NM_002936.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.749

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RNASEH1	NM_002936.6	c.703G>A	p.Gly235Arg	missense_variant	7/8	ENST00000315212.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RNASEH1	ENST00000315212.4	c.703G>A	p.Gly235Arg	missense_variant	7/8	1	NM_002936.6	P1
RNASEH1	ENST00000436842.5	c.*809G>A		3_prime_UTR_variant, NMD_transcript_variant	7/8	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461576 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727118

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 26, 2022

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. 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: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). This variant has not been reported in the literature in individuals affected with RNASEH1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 235 of the RNASEH1 protein (p.Gly235Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.40
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Uncertain	23
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.80	D
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.91	D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.75	D
MetaSVM	Benign	-0.49	T
MutationAssessor	Uncertain	2.3	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.51	T
PROVEAN	Pathogenic	-5.3	D
REVEL	Benign	0.27
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.0040	D
Polyphen		1.0	D
Vest4		0.50
MutPred		0.57		Gain of solvent accessibility (P = 0.0097);
MVP		0.78
MPC		1.0
ClinPred		0.98	D
GERP RS		5.4
Varity_R		0.78
gMVP		0.78

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-3595592; COSMIC: COSV59439883; COSMIC: COSV59439883;