2-55672999-G-T

Variant names:

• chr2-55672999-G-T
• rs778100619
• NM_033109.5:c.760C>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM2 PP5_Moderate BP4

The NM_033109.5(PNPT1):​c.760C>A​(p.Gln254Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,936 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. Q254Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PNPT1 NM_033109.5 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 9.48
• Publications: 3 publications found

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]

PNPT1 Gene-Disease associations (from GenCC):

• combined oxidative phosphorylation defect type 13

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• hearing loss disorder

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
• Leigh syndrome

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• spinocerebellar ataxia type 25

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• autosomal recessive nonsyndromic hearing loss 70

  Inheritance: Unknown, AR Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-55672999-G-T is Pathogenic according to our data. Variant chr2-55672999-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 253225.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP4: Computational evidence support a benign effect (MetaRNN=0.21872562). . Strength limited to SUPPORTING due to the PP5.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_033109.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PNPT1	NM_033109.5	MANE Select	c.760C>A	p.Gln254Lys	missense	Exon 9 of 28	NP_149100.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PNPT1	ENST00000447944.7	TSL:1 MANE Select	c.760C>A	p.Gln254Lys	missense	Exon 9 of 28	ENSP00000400646.2
	PNPT1	ENST00000917025.1		c.760C>A	p.Gln254Lys	missense	Exon 9 of 28	ENSP00000587084.1
	PNPT1	ENST00000867135.1		c.760C>A	p.Gln254Lys	missense	Exon 9 of 28	ENSP00000537194.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460936 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726786

African (AFR) AF: 0.00 AC: 0 AN: 33440

American (AMR) AF: 0.00 AC: 0 AN: 44654

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39658

South Asian (SAS) AF: 0.00 AC: 0 AN: 86200

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5356

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111768

Other (OTH) AF: 0.00 AC: 0 AN: 60326

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
2	-	-	Combined oxidative phosphorylation defect type 13 (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.087
BayesDel_addAF	Benign	-0.042	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	22
DANN	Benign	0.65
DEOGEN2	Benign	0.016	T
Eigen	Benign	-0.11
Eigen_PC	Benign	0.17
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Benign	0.010	T
MetaRNN	Benign	0.22	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.5	L
PhyloP100		9.5
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-0.23	N
REVEL	Benign	0.17
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Polyphen		0.0010	B
Vest4		0.49
MutPred		0.30		Gain of MoRF binding (P = 0.0277)
MVP		0.69
MPC		0.18
ClinPred		0.89	D
GERP RS		5.7
Varity_R		0.47
gMVP		0.60
Mutation Taster		=21/79	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs778100619; hg19: chr2-55900134;