chr2-55672999-G-C

Variant names:

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

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM2 PM5 BP4_Moderate

The NM_033109.5(PNPT1):​c.760C>G​(p.Gln254Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,460,936 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q254K) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PNPT1 NM_033109.5 missense
• Clinical Significance: Not reported in ClinVar
• 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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: 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=0.2249229).

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PNPT1	NM_033109.5	MANE Select	c.760C>G	p.Gln254Glu	missense	Exon 9 of 28	NP_149100.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PNPT1	ENST00000447944.7	TSL:1 MANE Select	c.760C>G	p.Gln254Glu	missense	Exon 9 of 28	ENSP00000400646.2
	PNPT1	ENST00000260604.8	TSL:5	n.*315C>G		non_coding_transcript_exon	Exon 8 of 27	ENSP00000260604.4
	PNPT1	ENST00000415374.5	TSL:5	n.760C>G		non_coding_transcript_exon	Exon 9 of 29	ENSP00000393953.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 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: 8.99e-7 AC: 1 AN: 1111768

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

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.092
BayesDel_addAF	Benign	-0.050	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	21
DANN	Benign	0.83
DEOGEN2	Benign	0.032	T
Eigen	Benign	-0.042
Eigen_PC	Benign	0.22
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Benign	0.0099	T
MetaRNN	Benign	0.22	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.2	M
PhyloP100		9.5
PrimateAI	Uncertain	0.57	T
PROVEAN	Benign	-0.77	N
REVEL	Benign	0.15
Sift	Benign	0.99	T
Sift4G	Benign	0.99	T
Polyphen		0.070	B
Vest4		0.47
MutPred		0.38		Loss of MoRF binding (P = 0.0393)
MVP		0.61
MPC		0.15
ClinPred		0.51	D
GERP RS		5.7
Varity_R		0.47
gMVP		0.53
Mutation Taster		=36/64	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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;