8-102205311-T-A

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 2P and 9B. PM2 BP4_Strong BP6 BS1

The NM_015713.5(RRM2B):c.*2822A>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000611 in 152,320 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00061 (0 hom., cov: 32)
  • Failed GnomAD Quality Control
• Consequence: RRM2B NM_015713.5 3_prime_UTR
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: -0.180

Genes affected

RRM2B (HGNC:17296): (ribonucleotide reductase regulatory TP53 inducible subunit M2B) This gene encodes the small subunit of a p53-inducible ribonucleotide reductase. This heterotetrameric enzyme catalyzes the conversion of ribonucleoside diphosphates to deoxyribonucleoside diphosphates. The product of this reaction is necessary for DNA synthesis. Mutations in this gene have been associated with autosomal recessive mitochondrial DNA depletion syndrome, autosomal dominant progressive external ophthalmoplegia-5, and mitochondrial neurogastrointestinal encephalopathy. Alternatively spliced transcript variants have been described.[provided by RefSeq, Feb 2010]

ACMG classification

Verdict is Benign. Variant got -7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.86).
• BP6: Variant 8-102205311-T-A is Benign according to our data. Variant chr8-102205311-T-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 361138.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Benign=1}.
• BS1: Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000611 (93/152320) while in subpopulation SAS AF= 0.00331 (16/4830). AF 95% confidence interval is 0.00208. There are 0 homozygotes in gnomad4. There are 44 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RRM2B	NM_015713.5	c.*2822A>T		3_prime_UTR_variant	9/9	ENST00000251810.8
RRM2B	NM_001172477.1	c.*2822A>T		3_prime_UTR_variant	9/9
RRM2B	NM_001172478.2	c.*2822A>T		3_prime_UTR_variant	8/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RRM2B	ENST00000251810.8	c.*2822A>T		3_prime_UTR_variant	9/9	1	NM_015713.5	P1

Frequencies

GnomAD3 genomes AF: 0.000611 AC: 93 AN: 152202 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000193

Gnomad AMI AF: 0.00110

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00310

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000956

Gnomad OTH AF: 0.00144

GnomAD4 exome Data not reliable, filtered out with message: AC0 AC: 0 AN: 0 Hom.: 0 Cov.: 0 AC XY: 0 AN XY: 0

GnomAD4 genome AF: 0.000611 AC: 93 AN: 152320 Hom.: 0 Cov.: 32 AF XY: 0.000591 AC XY: 44 AN XY: 74480

Gnomad4 AFR AF: 0.000192

Gnomad4 AMR AF: 0.0000653

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00331

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000941

Gnomad4 OTH AF: 0.00142

Alfa AF: 0.000139 Hom.: 0

Bravo AF: 0.000502

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Mitochondrial DNA depletion syndrome 8a Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 5 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
Cadd	Benign	0.61
Dann	Benign	0.77

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: rs189278573; hg19: chr8-103217539;