15-89333596-TTGCTGCTGCTGCTGCTGCTGCTGCTGCTGC-TTGCTGCTGCTGCTGCTGCTGCTGCTGCTGCTGCTGCTGC

Variant names:

• chr15-89333596-T-TTGCTGCTGC
• rs41550117
• ENST00000706918.1:c.205_213dupGCAGCAGCA

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP3 BP6_Very_Strong BS2

The NM_001430120.1(POLGARF):​c.205_213dupGCAGCAGCA​(p.Ala69_Ala71dup) variant causes a conservative inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00448 in 151,706 control chromosomes in the GnomAD database, including 3 homozygotes. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0045 (3 hom., cov: 30)
  • Exomes 𝑓: 0.0013 (3 hom.)
  • Failed GnomAD Quality Control
• Consequence: POLGARF NM_001430120.1 conservative_inframe_insertion
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:13
• Conservation: PhyloP100: -2.20

Genes affected

POLGARF (HGNC:56246): (POLG alternative reading frame) This gene uses the same transcript as the POLG gene but has a CUG start codon and an alternate reading frame that makes a 260 aa protein. This protein is distinct from POLG isoforms and may interact with P32 (also known as C1QBP), a mitochondrial matrix protein thought to be involved in the expression of mitochondrial genome-encoded proteins. POLGARF protein may bind P32 and sequester it in the nucleolus. Interestingly, some disease-causing mutations thought to be in POLG may instead be associated with POLGARF. [provided by RefSeq, May 2022]

POLG (HGNC:9179): (DNA polymerase gamma, catalytic subunit) Mitochondrial DNA polymerase is heterotrimeric, consisting of a homodimer of accessory subunits plus a catalytic subunit. The protein encoded by this gene is the catalytic subunit of mitochondrial DNA polymerase. The encoded protein contains a polyglutamine tract near its N-terminus that may be polymorphic. Defects in this gene are a cause of progressive external ophthalmoplegia with mitochondrial DNA deletions 1 (PEOA1), sensory ataxic neuropathy dysarthria and ophthalmoparesis (SANDO), Alpers-Huttenlocher syndrome (AHS), and mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE). Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Benign. Variant got -13 ACMG points.

• BP3: Nonframeshift variant in repetitive region in NM_001430120.1
• BP6: Variant 15-89333596-T-TTGCTGCTGC is Benign according to our data. Variant chr15-89333596-T-TTGCTGCTGC is described in ClinVar as [Likely_benign]. Clinvar id is 206482.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS2: High Homozygotes in GnomAd4 at 3 gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLG	NM_002693.3	c.150_158dupGCAGCAGCA	p.Gln51_Gln53dup	disruptive_inframe_insertion	Exon 2 of 23	ENST00000268124.11	NP_002684.1
POLGARF	NM_001430120.1	c.205_213dupGCAGCAGCA	p.Ala69_Ala71dup	conservative_inframe_insertion	Exon 1 of 2		NP_001417049.1
POLG	NM_001126131.2	c.150_158dupGCAGCAGCA	p.Gln51_Gln53dup	disruptive_inframe_insertion	Exon 2 of 23		NP_001119603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLGARF	ENST00000706918.1	c.205_213dupGCAGCAGCA	p.Ala69_Ala71dup	conservative_inframe_insertion	Exon 1 of 2			ENSP00000516626.1
POLG	ENST00000268124.11	c.150_158dupGCAGCAGCA	p.Gln51_Gln53dup	disruptive_inframe_insertion	Exon 2 of 23	1	NM_002693.3	ENSP00000268124.5

Frequencies

GnomAD3 genomes AF: 0.00449 AC: 681 AN: 151602 Hom.: 4 Cov.: 30

Gnomad AFR AF: 0.0135

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00118

Gnomad ASJ AF: 0.000289

Gnomad EAS AF: 0.00135

Gnomad SAS AF: 0.00125

Gnomad FIN AF: 0.00189

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000973

Gnomad OTH AF: 0.00241

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00127 AC: 1831 AN: 1446392 Hom.: 3 Cov.: 31 AF XY: 0.00118 AC XY: 847 AN XY: 719194

Gnomad4 AFR exome AF: 0.0131

Gnomad4 AMR exome AF: 0.000934

Gnomad4 ASJ exome AF: 0.000271

Gnomad4 EAS exome AF: 0.000634

Gnomad4 SAS exome AF: 0.000528

Gnomad4 FIN exome AF: 0.00158

Gnomad4 NFE exome AF: 0.00100

Gnomad4 OTH exome AF: 0.00147

GnomAD4 genome AF: 0.00448 AC: 680 AN: 151706 Hom.: 3 Cov.: 30 AF XY: 0.00440 AC XY: 326 AN XY: 74158

Gnomad4 AFR AF: 0.0135

Gnomad4 AMR AF: 0.00118

Gnomad4 ASJ AF: 0.000289

Gnomad4 EAS AF: 0.00136

Gnomad4 SAS AF: 0.00125

Gnomad4 FIN AF: 0.00189

Gnomad4 NFE AF: 0.000973

Gnomad4 OTH AF: 0.00239

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:13

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:5

Apr 06, 2015

Genetic Services Laboratory, University of Chicago

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Apr 13, 2017

Eurofins Ntd Llc (ga)

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 19, 2014

GeneDx

Significance: Benign

Review Status: flagged submission

Collection Method: clinical testing

The variant is found in POLG panel(s). -

-

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided Benign:5

-

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Mar 03, 2015

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 29, 2016

Mayo Clinic Laboratories, Mayo Clinic

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Feb 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

POLG: BS1, BS2 -

Aug 26, 2015

Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Progressive sclerosing poliodystrophy;C1834846:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 1;C1843851:Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis;C3150914:Mitochondrial DNA depletion syndrome 4b;C4225153:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 1;C4551995:Mitochondrial DNA depletion syndrome 1 Benign:1

Sep 23, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases Benign:1

Sep 14, 2017

Ambry Genetics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Progressive sclerosing poliodystrophy Benign:1

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs41550117; hg19: chr15-89876827;