15-89317492-G-T

Variant names:

• chr15-89317492-G-T
• rs776031396
• NM_002693.3:c.3527C>A

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_002693.3(POLG):​c.3527C>A​(p.Ser1176*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POLG NM_002693.3 stop_gained
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.60
• Publications: 3 publications found

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]

FANCI (HGNC:25568): (FA complementation group I) The Fanconi anemia complementation group (FANC) currently includes FANCA, FANCB, FANCC, FANCD1 (also called BRCA2), FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ (also called BRIP1), FANCL, FANCM and FANCN (also called PALB2). The previously defined group FANCH is the same as FANCA. Fanconi anemia is a genetically heterogeneous recessive disorder characterized by cytogenetic instability, hypersensitivity to DNA crosslinking agents, increased chromosomal breakage, and defective DNA repair. The members of the Fanconi anemia complementation group do not share sequence similarity; they are related by their assembly into a common nuclear protein complex. This gene encodes the protein for complementation group I. Alternative splicing results in two transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

FANCI Gene-Disease associations (from GenCC):

• Fanconi anemia complementation group I

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P
• Fanconi anemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 15-89317492-G-T is Pathogenic according to our data. Variant chr15-89317492-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 383185.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002693.3. 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
	POLG	NM_002693.3	MANE Select	c.3527C>A	p.Ser1176*	stop_gained	Exon 22 of 23	NP_002684.1
	POLG	NM_001126131.2		c.3527C>A	p.Ser1176*	stop_gained	Exon 22 of 23	NP_001119603.1
	FANCI	NM_018193.3		c.*1033G>T		downstream_gene	N/A	NP_060663.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POLG	ENST00000268124.11	TSL:1 MANE Select	c.3527C>A	p.Ser1176*	stop_gained	Exon 22 of 23	ENSP00000268124.5
	POLG	ENST00000442287.6	TSL:1	c.3527C>A	p.Ser1176*	stop_gained	Exon 22 of 23	ENSP00000399851.2
	POLG	ENST00000636937.2	TSL:5	c.3527C>A	p.Ser1176*	stop_gained	Exon 22 of 23	ENSP00000516154.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Feb 09, 2016

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The S1176X variant in the POLG gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The S1176X variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. We interpret S1176X as a likely pathogenic variant, however the possibility it may be a rare benign variant cannot be excluded.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	52
DANN	Uncertain	1.0
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.97	D
PhyloP100		9.6
Vest4		0.96
GERP RS		5.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.23		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.23		Position offset: -16

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

Other links and lift over

dbSNP: rs776031396; hg19: chr15-89860723;