2-55636286-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_033109.5(PNPT1):c.2303G>T(p.Ser768Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,594 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: PNPT1 NM_033109.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.41

Genes affected

PNPT1 (HGNC:23166): (polyribonucleotide nucleotidyltransferase 1) The protein encoded by this gene belongs to the evolutionary conserved polynucleotide phosphorylase family comprised of phosphate dependent 3'-to-5' exoribonucleases implicated in RNA processing and degradation. This enzyme is predominantly localized in the mitochondrial intermembrane space and is involved in import of RNA to mitochondria. Mutations in this gene have been associated with combined oxidative phosphorylation deficiency-13 and autosomal recessive nonsyndromic deafness-70. Related pseudogenes are found on chromosomes 3 and 7. [provided by RefSeq, Dec 2012]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17675251).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PNPT1	NM_033109.5	c.2303G>T	p.Ser768Ile	missense_variant	28/28	ENST00000447944.7
PNPT1	XM_005264629.3	c.2063G>T	p.Ser688Ile	missense_variant	28/28
PNPT1	XM_017005172.2	c.2063G>T	p.Ser688Ile	missense_variant	27/27

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PNPT1	ENST00000447944.7	c.2303G>T	p.Ser768Ile	missense_variant	28/28	1	NM_033109.5	P1
PNPT1	ENST00000415374.5	c.2303G>T	p.Ser768Ile	missense_variant, NMD_transcript_variant	28/29	5
PNPT1	ENST00000260604.8	c.*1845G>T		3_prime_UTR_variant, NMD_transcript_variant	27/27	5

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152044 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000656

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251098 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135800

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1461436 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 AN XY: 727070

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152158 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74382

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ExAC AF: 0.00000824 AC: 1

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

Invitae

Oct 25, 2021

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: "Benign"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with PNPT1-related conditions. This variant is present in population databases (rs566113211, gnomAD 0.003%). This sequence change replaces serine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 768 of the PNPT1 protein (p.Ser768Ile). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Benign	-0.041	T
BayesDel_noAF	Benign	-0.21
Cadd	Uncertain	25
Dann	Uncertain	0.99
DEOGEN2	Benign	0.038	T
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.18	T
MetaSVM	Benign	-0.80	T
MutationAssessor	Uncertain	2.0	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.51	T
PROVEAN	Benign	-1.9	N
REVEL	Benign	0.12
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.011	D
Polyphen		0.90	P
Vest4		0.45
MutPred		0.41		Loss of phosphorylation at S768 (P = 0.0189);
MVP		0.22
MPC		0.20
ClinPred		0.84	D
GERP RS		5.1
Varity_R		0.41
gMVP		0.45

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: rs566113211; hg19: chr2-55863421;