rs41540414

Positions:

• chr15-89330084-G-A
• chr15-89330084-G-C

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_Strong BP6_Very_Strong BP7 BS1 BS2

The NM_002693.3(POLG):​c.852C>T​(p.Ile284Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000591 in 1,612,140 control chromosomes in the GnomAD database, including 6 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0031 (2 hom., cov: 32)
  • Exomes 𝑓: 0.00033 (4 hom.)
• Consequence: POLG NM_002693.3 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:7
• Conservation: PhyloP100: 1.36

Genes affected

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 -21 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.5).
• BP6: Variant 15-89330084-G-A is Benign according to our data. Variant chr15-89330084-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 138770.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-89330084-G-A is described in Lovd as [Likely_benign].
• BP7: Synonymous conserved (PhyloP=1.36 with no splicing effect.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00309 (471/152306) while in subpopulation AFR AF= 0.0108 (448/41564). AF 95% confidence interval is 0.00995. There are 2 homozygotes in gnomad4. There are 219 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd4 at 2 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLG	NM_002693.3	c.852C>T	p.Ile284Ile	synonymous_variant	3/23	ENST00000268124.11	NP_002684.1
POLG	NM_001126131.2	c.852C>T	p.Ile284Ile	synonymous_variant	3/23		NP_001119603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLG	ENST00000268124.11	c.852C>T	p.Ile284Ile	synonymous_variant	3/23	1	NM_002693.3	ENSP00000268124.5

Frequencies

GnomAD3 genomes AF: 0.00309 AC: 471 AN: 152188 Hom.: 2 Cov.: 32

Gnomad AFR AF: 0.0108

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00124

Gnomad ASJ AF: 0.000865

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000479

GnomAD3 exomes AF: 0.000829 AC: 208 AN: 251006 Hom.: 0 AF XY: 0.000722 AC XY: 98 AN XY: 135736

Gnomad AFR exome AF: 0.0109

Gnomad AMR exome AF: 0.000376

Gnomad ASJ exome AF: 0.00119

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000441

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.000329 AC: 481 AN: 1459834 Hom.: 4 Cov.: 32 AF XY: 0.000275 AC XY: 200 AN XY: 726338

Gnomad4 AFR exome AF: 0.0112

Gnomad4 AMR exome AF: 0.000537

Gnomad4 ASJ exome AF: 0.000957

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000991

Gnomad4 OTH exome AF: 0.000762

GnomAD4 genome AF: 0.00309 AC: 471 AN: 152306 Hom.: 2 Cov.: 32 AF XY: 0.00294 AC XY: 219 AN XY: 74478

Gnomad4 AFR AF: 0.0108

Gnomad4 AMR AF: 0.00124

Gnomad4 ASJ AF: 0.000865

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.000474

Alfa AF: 0.00175 Hom.: 1

Bravo AF: 0.00391

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:3

Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jul 17, 2017	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Nov 05, 2013	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Likely benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -

Progressive sclerosing poliodystrophy Benign:2

Benign, criteria provided, single submitter	clinical testing	Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine	Oct 01, 2018	The NM_002693.2:c.852C>T (NP_002684.1:p.Ile284=) [GRCH38: NC_000015.10:g.89330084G>A] variant in POLG gene is interpretated to be a Benign based on ACMG guidelines (PMID: 25741868). This variant meets the following evidence codes reported in the ACMG-guideline. BS1:The minor allele frequency of this allele is high for Mitochondrial DNA depletion syndrome 4A (Alpers type). BS2:Observation of the variant in controls is inconsistent with penetrance of Mitochondrial DNA depletion syndrome 4A (Alpers type). Based on the evidence criteria codes applied, the variant is suggested to be Benign. -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 01, 2024	- -

Inborn genetic diseases Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 27, 2016

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. -

not provided Benign:1

Likely benign, criteria provided, single submitter

not provided

Breakthrough Genomics, Breakthrough Genomics

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.50
CADD	Benign	9.1
DANN	Benign	0.74

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

Publications

LitVar

Other links and lift over

dbSNP: rs41540414; hg19: chr15-89873315;