3-131468063-GAAA-GAAAAA

Variant names:

• chr3-131468063-G-GAA
• rs374998359
• NM_007208.4:c.894+26_894+27dupTT

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_007208.4(MRPL3):​c.894+26_894+27dupTT variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000805 in 994,150 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 29)
  • Exomes 𝑓: 0.0000080 (0 hom.)
• Consequence: MRPL3 NM_007208.4 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.70
• Publications: 0 publications found

Genes affected

MRPL3 (HGNC:10379): (mitochondrial ribosomal protein L3) 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 39S subunit protein that belongs to the L3P ribosomal protein family. A pseudogene corresponding to this gene is found on chromosome 13q. [provided by RefSeq, Jul 2008]

MRPL3 Gene-Disease associations (from GenCC):

• combined oxidative phosphorylation defect type 9

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• mitochondrial disease

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_007208.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MRPL3	NM_007208.4	MANE Select	c.894+26_894+27dupTT		intron	N/A	NP_009139.1	P09001

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MRPL3	ENST00000264995.8	TSL:1 MANE Select	c.894+27_894+28insTT		intron	N/A	ENSP00000264995.2	P09001
	MRPL3	ENST00000425847.6	TSL:2	c.975+27_975+28insTT		intron	N/A	ENSP00000398536.2	E7ETU7
	MRPL3	ENST00000511168.5	TSL:2	c.936+27_936+28insTT		intron	N/A	ENSP00000424107.1	H0Y9G6

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome AF: 0.00000805 AC: 8 AN: 994150 Hom.: 0 Cov.: 12 AF XY: 0.00000796 AC XY: 4 AN XY: 502606

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 19916

American (AMR) AF: 0.00 AC: 0 AN: 20900

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 18032

East Asian (EAS) AF: 0.00 AC: 0 AN: 31440

South Asian (SAS) AF: 0.00 AC: 0 AN: 51204

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 46006

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4204

European-Non Finnish (NFE) AF: 0.0000105 AC: 8 AN: 760540

Other (OTH) AF: 0.00 AC: 0 AN: 41908

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 29

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-2.7

Splicing

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

Other links and lift over

dbSNP: rs374998359; hg19: chr3-131186907;