15-89333596-TTGCTGCTGCTGCTGCTGCTGCTGCTGCTGC-TTGCTGCTGCTGCTGCTGC

Position:

• chr15-89333596-TTGCTGCTGCTGCTGCTGCTGCTGCTGCTGC-TTGCTGCTGCTGCTGCTGC

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP3 BP6 BS2

The NM_001406557.1(POLGARF):​c.202_213delGCAGCAGCAGCA​(p.Ala68_Ala71del) variant causes a conservative inframe deletion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000693 in 1,598,102 control chromosomes in the GnomAD database, including 4 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0011 (1 hom., cov: 30)
  • Exomes 𝑓: 0.00065 (3 hom.)
• Consequence: POLGARF NM_001406557.1 conservative_inframe_deletion
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:7
• Conservation: PhyloP100: 0.0750

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]

POLGARF (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• BP3: Nonframeshift variant in repetitive region in NM_001406557.1
• BP6: Variant 15-89333596-TTGCTGCTGCTGC-T is Benign according to our data. Variant chr15-89333596-TTGCTGCTGCTGC-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 206480.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=5, Uncertain_significance=1, Benign=1}. Variant chr15-89333596-TTGCTGCTGCTGC-T is described in Lovd as [Likely_benign].
• BS2: High Homozygotes in GnomAdExome4 at 3 gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLG	NM_002693.3	c.147_158delGCAGCAGCAGCA	p.Gln50_Gln53del	disruptive_inframe_deletion	2/23	ENST00000268124.11	NP_002684.1
POLGARF	NM_001406557.1	c.202_213delGCAGCAGCAGCA	p.Ala68_Ala71del	conservative_inframe_deletion	2/23
POLG	NM_001126131.2	c.147_158delGCAGCAGCAGCA	p.Gln50_Gln53del	disruptive_inframe_deletion	2/23		NP_001119603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLGARF	ENST00000706918.1	c.202_213delGCAGCAGCAGCA	p.Ala68_Ala71del	conservative_inframe_deletion	1/2			ENSP00000516626.1
POLG	ENST00000268124.11	c.147_158delGCAGCAGCAGCA	p.Gln50_Gln53del	disruptive_inframe_deletion	2/23	1	NM_002693.3	ENSP00000268124.5

Frequencies

GnomAD3 genomes AF: 0.00113 AC: 172 AN: 151604 Hom.: 1 Cov.: 30

Gnomad AFR AF: 0.00201

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00118

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000386

Gnomad SAS AF: 0.00229

Gnomad FIN AF: 0.000284

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000766

Gnomad OTH AF: 0.00145

GnomAD4 exome AF: 0.000646 AC: 935 AN: 1446394 Hom.: 3 AF XY: 0.000709 AC XY: 510 AN XY: 719198

Gnomad4 AFR exome AF: 0.00177

Gnomad4 AMR exome AF: 0.00114

Gnomad4 ASJ exome AF: 0.0000387

Gnomad4 EAS exome AF: 0.000203

Gnomad4 SAS exome AF: 0.00211

Gnomad4 FIN exome AF: 0.000562

Gnomad4 NFE exome AF: 0.000510

Gnomad4 OTH exome AF: 0.000703

GnomAD4 genome AF: 0.00113 AC: 172 AN: 151708 Hom.: 1 Cov.: 30 AF XY: 0.00124 AC XY: 92 AN XY: 74160

Gnomad4 AFR AF: 0.00201

Gnomad4 AMR AF: 0.00118

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000387

Gnomad4 SAS AF: 0.00229

Gnomad4 FIN AF: 0.000284

Gnomad4 NFE AF: 0.000766

Gnomad4 OTH AF: 0.00143

Bravo AF: 0.00112

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:7

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Benign:3

Benign, criteria provided, single submitter	clinical testing	GeneDx	Dec 29, 2014	The variant is found in MITONUC-MITOP,CHILD-EPI,INFANT-EPI panel(s). -
Likely benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Apr 27, 2016	- -
Likely benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	May 15, 2024	- -

not provided Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jun 01, 2024	POLG: BP3 -
Uncertain significance, criteria provided, single submitter	clinical testing	Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center	Dec 07, 2023	BP3 -

Inborn genetic diseases Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 07, 2022

This alteration is classified as likely 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. -

Hereditary spastic paraplegia Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Genome Diagnostics Laboratory, The Hospital for Sick Children

Dec 15, 2016

- -

Progressive sclerosing poliodystrophy Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

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;