NM_033109.5:c.*71T>G

Variant names:

• chr2-55636166-A-C
• rs72930820
• NM_033109.5:c.*71T>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_033109.5(PNPT1):​c.*71T>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000105 in 956,498 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000010 (0 hom.)
• Consequence: PNPT1 NM_033109.5 3_prime_UTR
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.560
• Publications: 0 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, Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
• 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: AR, Unknown Classification: LIMITED Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.87).

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.*71T>G		3_prime_UTR	Exon 28 of 28	NP_149100.2	Q8TCS8

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PNPT1	ENST00000447944.7	TSL:1 MANE Select	c.*71T>G		3_prime_UTR	Exon 28 of 28	ENSP00000400646.2	Q8TCS8
	PNPT1	ENST00000917025.1		c.*71T>G		3_prime_UTR	Exon 28 of 28	ENSP00000587084.1
	PNPT1	ENST00000867135.1		c.*71T>G		3_prime_UTR	Exon 28 of 28	ENSP00000537194.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000105 AC: 1 AN: 956498 Hom.: 0 Cov.: 12 AF XY: 0.00 AC XY: 0 AN XY: 481074

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 22416

American (AMR) AF: 0.00 AC: 0 AN: 23446

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 18752

East Asian (EAS) AF: 0.00 AC: 0 AN: 35182

South Asian (SAS) AF: 0.00 AC: 0 AN: 54846

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 39334

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3032

European-Non Finnish (NFE) AF: 0.00000139 AC: 1 AN: 717098

Other (OTH) AF: 0.00 AC: 0 AN: 42392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.87
CADD	Benign	1.6
DANN	Benign	0.48
PhyloP100		-0.56

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: rs72930820; hg19: chr2-55863301;