19-12806717-G-A

Position:

• chr19-12806717-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The NM_006397.3(RNASEH2A):​c.44G>A​(p.Arg15His) 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. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: RNASEH2A NM_006397.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.73

Genes affected

RNASEH2A (HGNC:18518): (ribonuclease H2 subunit A) The protein encoded by this gene is a component of the heterotrimeric type II ribonuclease H enzyme (RNAseH2). RNAseH2 is the major source of ribonuclease H activity in mammalian cells and endonucleolytically cleaves ribonucleotides. It is predicted to remove Okazaki fragment RNA primers during lagging strand DNA synthesis and to excise single ribonucleotides from DNA-DNA duplexes. Mutations in this gene cause Aicardi-Goutieres Syndrome (AGS), a an autosomal recessive neurological disorder characterized by progressive microcephaly and psychomotor retardation, intracranial calcifications, elevated levels of interferon-alpha and white blood cells in the cerebrospinal fluid.[provided by RefSeq, Aug 2009]

THSD8 (HGNC:53785): (thrombospondin type 1 domain containing 8)

HOOK2 (HGNC:19885): (hook microtubule tethering protein 2) Hook proteins are cytosolic coiled-coil proteins that contain conserved N-terminal domains, which attach to microtubules, and more divergent C-terminal domains, which mediate binding to organelles. The Drosophila Hook protein is a component of the endocytic compartment.[supplied by OMIM, Apr 2004]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a chain Ribonuclease H2 subunit A (size 298) in uniprot entity RNH2A_HUMAN there are 15 pathogenic changes around while only 6 benign (71%) in NM_006397.3
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3031361).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RNASEH2A	NM_006397.3	c.44G>A	p.Arg15His	missense_variant	1/8	ENST00000221486.6	NP_006388.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RNASEH2A	ENST00000221486.6	c.44G>A	p.Arg15His	missense_variant	1/8	1	NM_006397.3	ENSP00000221486	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Aicardi-Goutieres syndrome 4 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 31, 2019

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: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with RNASEH2A-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with histidine at codon 15 of the RNASEH2A protein (p.Arg15His). The arginine residue is moderately conserved and there is a small physicochemical difference between arginine and histidine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Uncertain	0.065	T
BayesDel_noAF	Benign	-0.14
CADD	Benign	23
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.27	T;.
Eigen	Benign	-0.034
Eigen_PC	Benign	0.034
FATHMM_MKL	Benign	0.69	D
LIST_S2	Uncertain	0.87	D;D
M_CAP	Benign	0.045	D
MetaRNN	Benign	0.30	T;T
MetaSVM	Benign	-0.74	T
MutationAssessor	Uncertain	2.4	M;.
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.69	T
PROVEAN	Benign	-0.84	N;.
REVEL	Uncertain	0.38
Sift	Benign	0.26	T;.
Sift4G	Uncertain	0.034	D;.
Polyphen		0.72	P;.
Vest4		0.67
MutPred		0.28		Loss of methylation at R15 (P = 0.0336);.;
MVP		0.87
MPC		0.77
ClinPred		0.93	D
GERP RS		2.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
Varity_R		0.33
gMVP		0.68

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

LitVar

Other links and lift over

dbSNP: rs1968995083; hg19: chr19-12917531;