chr16-1772956-C-T

Position:

• chr16-1772956-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_023936.2(MRPS34):​c.164G>A​(p.Trp55Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000231 in 1,297,392 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 35)
  • Exomes 𝑓: 0.0000023 (0 hom.)
• Consequence: MRPS34 NM_023936.2 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.33

Genes affected

MRPS34 (HGNC:16618): (mitochondrial ribosomal protein S34) Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. This gene encodes a 28S subunit protein. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2014]

EME2 (HGNC:27289): (essential meiotic structure-specific endonuclease subunit 2) EME2 forms a heterodimer with MUS81 (MIM 606591) that functions as an XPF (MIM 278760)-type flap/fork endonuclease in DNA repair (Ciccia et al., 2007 [PubMed 17289582]).[supplied by OMIM, Mar 2008]

ACMG classification

Verdict is Pathogenic. Variant got 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 16-1772956-C-T is Pathogenic according to our data. Variant chr16-1772956-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 2876971.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MRPS34	NM_023936.2	c.164G>A	p.Trp55Ter	stop_gained	1/3	ENST00000397375.7
EME2	NM_001257370.2	c.-272C>T		5_prime_UTR_variant	1/8	ENST00000568449.7
MRPS34	NM_001300900.2	c.164G>A	p.Trp55Ter	stop_gained	1/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MRPS34	ENST00000397375.7	c.164G>A	p.Trp55Ter	stop_gained	1/3	1	NM_023936.2	P1
MRPS34	ENST00000177742.7	c.164G>A	p.Trp55Ter	stop_gained	1/3	1
EME2	ENST00000568449.7	c.-272C>T		5_prime_UTR_variant	1/8	1	NM_001257370.2	P1

Frequencies

GnomAD3 genomes Cov.: 35

GnomAD4 exome AF: 0.00000231 AC: 3 AN: 1297392 Hom.: 0 Cov.: 62 AF XY: 0.00000158 AC XY: 1 AN XY: 634696

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000289

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 35

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 22, 2023

This sequence change creates a premature translational stop signal (p.Trp55*) in the MRPS34 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MRPS34 are known to be pathogenic (PMID: 28777931). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MRPS34-related conditions. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	43
DANN	Uncertain	0.99
Eigen	Pathogenic	0.78
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Uncertain	0.94	D
MutationTaster	Benign	1.0	A;A;A
Vest4		0.17
GERP RS		4.2
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.1

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: rs1018543927; hg19: chr16-1822957;