16-14436756-G-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_002582.4(PARN):c.1881C>A(p.Asn627Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000416 in 1,442,490 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000042 (0 hom.)
• Consequence: PARN NM_002582.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.378

Genes affected

PARN (HGNC:8609): (poly(A)-specific ribonuclease) The protein encoded by this gene is a 3'-exoribonuclease, with similarity to the RNase D family of 3'-exonucleases. It prefers poly(A) as the substrate, hence, efficiently degrades poly(A) tails of mRNAs. Exonucleolytic degradation of the poly(A) tail is often the first step in the decay of eukaryotic mRNAs. This protein is also involved in silencing of certain maternal mRNAs during oocyte maturation and early embryonic development, as well as in nonsense-mediated decay (NMD) of mRNAs that contain premature stop codons. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.07505697).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PARN	NM_002582.4	c.1881C>A	p.Asn627Lys	missense_variant	24/24	ENST00000437198.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PARN	ENST00000437198.7	c.1881C>A	p.Asn627Lys	missense_variant	24/24	1	NM_002582.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000465 AC: 1 AN: 214848 Hom.: 0 AF XY: 0.00000865 AC XY: 1 AN XY: 115628

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000377

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000416 AC: 6 AN: 1442490 Hom.: 0 Cov.: 29 AF XY: 0.00000559 AC XY: 4 AN XY: 715456

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000725

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000829 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Pulmonary fibrosis and/or bone marrow failure, Telomere-related, 4;C4225356:Dyskeratosis congenita, autosomal recessive 6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 04, 2022

This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 627 of the PARN protein (p.Asn627Lys). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with PARN-related conditions. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.096
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.60
Cadd	Benign	15
Dann	Uncertain	0.98
DEOGEN2	Benign	0.015	T;.;.;.
Eigen	Benign	-0.57
Eigen_PC	Benign	-0.44
FATHMM_MKL	Benign	0.36	N
LIST_S2	Benign	0.53	T;T;T;T
M_CAP	Benign	0.0065	T
MetaRNN	Benign	0.075	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.0	N;.;.;.
MutationTaster	Benign	1.0	N;N;N;N
PrimateAI	Benign	0.30	T
PROVEAN	Benign	-0.29	N;N;N;N
REVEL	Benign	0.063
Sift	Benign	0.082	T;T;T;T
Sift4G	Benign	0.92	T;T;T;T
Polyphen		0.0010	B;.;.;.
Vest4		0.086
MutPred		0.17		Gain of ubiquitination at N627 (P = 0.0018);.;.;.;
MVP		0.28
MPC		0.16
ClinPred		0.027	T
GERP RS		2.2
Varity_R		0.039
gMVP		0.074

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs777806186; hg19: chr16-14530613;