chr12-123253728-G-A

Position:

• chr12-123253728-G-A

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6 BP7

The NM_152269.5(MTRFR):​c.54G>A​(p.Pro18=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00016 in 1,614,088 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 0.00030 (0 hom., cov: 31)
  • Exomes 𝑓: 0.00015 (0 hom.)
• Consequence: MTRFR NM_152269.5 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: -5.99

Genes affected

MTRFR (HGNC:26784): (mitochondrial translation release factor in rescue) This nuclear gene encodes a mitochondrial matrix protein that appears to contribute to peptide chain termination in the mitochondrial translation machinery. Two different 1 bp deletions (resulting in the same premature stop codon)result in decreased mitochondrial translation, decreased levels of oxidative phosphorylation complexes and encepthalomyopathy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2010]

CDK2AP1 (HGNC:14002): (cyclin dependent kinase 2 associated protein 1) The protein encoded by this gene is a cyclin-dependent kinase 2 (CDK2) -associated protein which is thought to negatively regulate CDK2 activity by sequestering monomeric CDK2, and targeting CDK2 for proteolysis. This protein was found to also interact with DNA polymerase alpha/primase and mediate the phosphorylation of the large p180 subunit, which suggests a regulatory role in DNA replication during the S-phase of the cell cycle. This protein also forms a core subunit of the nucleosome remodeling and histone deacetylation (NURD) complex that epigenetically regulates embryonic stem cell differentiation. This gene thus plays a role in both cell-cycle and epigenetic regulation. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2012]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).
• BP6: Variant 12-123253728-G-A is Benign according to our data. Variant chr12-123253728-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 697230.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=1}. Variant chr12-123253728-G-A is described in Lovd as [Likely_benign].
• BP7: Synonymous conserved (PhyloP=-5.99 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MTRFR	NM_152269.5	c.54G>A	p.Pro18=	synonymous_variant	2/3	ENST00000253233.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MTRFR	ENST00000253233.6	c.54G>A	p.Pro18=	synonymous_variant	2/3	1	NM_152269.5	P1

Frequencies

GnomAD3 genomes AF: 0.000302 AC: 46 AN: 152080 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.000555

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000590

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00633

Gnomad NFE AF: 0.000103

Gnomad OTH AF: 0.000959

GnomAD3 exomes AF: 0.000203 AC: 51 AN: 251402 Hom.: 0 AF XY: 0.000169 AC XY: 23 AN XY: 135874

Gnomad AFR exome AF: 0.000677

Gnomad AMR exome AF: 0.000463

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000217

Gnomad SAS exome AF: 0.0000980

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000123

Gnomad OTH exome AF: 0.000489

GnomAD4 exome AF: 0.000145 AC: 212 AN: 1461890 Hom.: 0 Cov.: 31 AF XY: 0.000153 AC XY: 111 AN XY: 727246

Gnomad4 AFR exome AF: 0.000777

Gnomad4 AMR exome AF: 0.000581

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000353

Gnomad4 SAS exome AF: 0.000209

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000908

Gnomad4 OTH exome AF: 0.000364

GnomAD4 genome AF: 0.000302 AC: 46 AN: 152198 Hom.: 0 Cov.: 31 AF XY: 0.000202 AC XY: 15 AN XY: 74410

Gnomad4 AFR AF: 0.000554

Gnomad4 AMR AF: 0.000589

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.000415

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000103

Gnomad4 OTH AF: 0.000949

Alfa AF: 0.000174 Hom.: 0

Bravo AF: 0.000344

EpiCase AF: 0.000164

EpiControl AF: 0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary spastic paraplegia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome Diagnostics Laboratory, The Hospital for Sick Children

Nov 12, 2021

- -

Spastic paraplegia;C3150801:Combined oxidative phosphorylation defect type 7 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 17, 2024

- -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Jun 01, 2023

MTRFR: BP4, BP7 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.85
CADD	Benign	0.030
DANN	Benign	0.89
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs188310109; hg19: chr12-123738275;