NM_007254.4:c.539G>A

Variant names:

• chr19-49864363-C-T
• rs779492301
• NM_007254.4:c.539G>A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_007254.4(PNKP):​c.539G>A​(p.Arg180His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,754 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R180S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: PNKP NM_007254.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.360

Genes affected

PNKP (HGNC:9154): (polynucleotide kinase 3'-phosphatase) This locus represents a gene involved in DNA repair. In response to ionizing radiation or oxidative damage, the protein encoded by this locus catalyzes 5' phosphorylation and 3' dephosphorylation of nucleic acids. Mutations at this locus have been associated with microcephaly, seizures, and developmental delay.[provided by RefSeq, Sep 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.30478534).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PNKP	NM_007254.4	c.539G>A	p.Arg180His	missense_variant	Exon 5 of 17	ENST00000322344.8	NP_009185.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PNKP	ENST00000322344.8	c.539G>A	p.Arg180His	missense_variant	Exon 5 of 17	1	NM_007254.4	ENSP00000323511.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251450 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135916

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: 0.00000274 AC: 4 AN: 1461754 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727212

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Nov 21, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.539G>A (p.R180H) alteration is located in exon 5 (coding exon 4) of the PNKP gene. This alteration results from a G to A substitution at nucleotide position 539, causing the arginine (R) at amino acid position 180 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Developmental and epileptic encephalopathy, 12 Uncertain:1

Aug 26, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine with histidine at codon 180 of the PNKP protein (p.Arg180His). The arginine residue is moderately conserved and there is a small physicochemical difference between arginine and histidine. This variant is present in population databases (rs779492301, ExAC 0.009%). This variant has not been reported in the literature in individuals affected with PNKP-related conditions. 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: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.088
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.38
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.098	T;T;T;T;T;.
Eigen	Benign	-0.30
Eigen_PC	Benign	-0.35
FATHMM_MKL	Benign	0.072	N
LIST_S2	Pathogenic	0.98	D;.;D;D;D;D
M_CAP	Benign	0.042	D
MetaRNN	Benign	0.30	T;T;T;T;T;T
MetaSVM	Benign	-0.95	T
MutationAssessor	Benign	1.9	.;L;.;L;.;.
PrimateAI	Benign	0.42	T
PROVEAN	Uncertain	-2.8	.;D;.;.;.;.
REVEL	Benign	0.18
Sift	Uncertain	0.016	.;D;.;.;.;.
Sift4G	Uncertain	0.015	D;D;D;D;D;.
Polyphen		0.96	.;P;.;P;.;.
Vest4		0.36
MutPred		0.61		Gain of ubiquitination at K183 (P = 0.0436);Gain of ubiquitination at K183 (P = 0.0436);Gain of ubiquitination at K183 (P = 0.0436);Gain of ubiquitination at K183 (P = 0.0436);Gain of ubiquitination at K183 (P = 0.0436);Gain of ubiquitination at K183 (P = 0.0436);
MVP		0.67
MPC		0.34
ClinPred		0.97	D
GERP RS		2.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.16
gMVP		0.43

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs779492301; hg19: chr19-50367620; COSMIC: COSV55587735; COSMIC: COSV55587735;