3-3129041-ATGCTGAGG-A

Position:

• chr3-3129041-ATGCTGAGG-A

Variant summary

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

The NM_182916.3(TRNT1):​c.5_12del​(p.Leu2_?4) variant causes a frameshift, start lost change. The variant allele was found at a frequency of 0.00000657 in 152,144 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: TRNT1 NM_182916.3 frameshift, start_lost
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.39

Genes affected

TRNT1 (HGNC:17341): (tRNA nucleotidyl transferase 1) The protein encoded by this gene is a CCA-adding enzyme which belongs to the tRNA nucleotidyltransferase/poly(A) polymerase family. This essential enzyme functions by catalyzing the addition of the conserved nucleotide triplet CCA to the 3' terminus of tRNA molecules. Mutations in this gene result in sideroblastic anemia with B-cell immunodeficiency, periodic fevers, and developmental delay. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2014]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 40 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-3129041-ATGCTGAGG-A is Pathogenic according to our data. Variant chr3-3129041-ATGCTGAGG-A is described in ClinVar as [Pathogenic]. Clinvar id is 3017738.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TRNT1	NM_182916.3	c.5_12del	p.Leu2_?4	frameshift_variant, start_lost	2/8	ENST00000251607.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TRNT1	ENST00000251607.11	c.5_12del	p.Leu2_?4	frameshift_variant, start_lost	2/8	1	NM_182916.3	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152144 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152144 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74342

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital sideroblastic anemia-B-cell immunodeficiency-periodic fever-developmental delay syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 03, 2023

For these reasons, this variant has been classified as Pathogenic. This variant has not been reported in the literature in individuals affected with TRNT1-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change creates a premature translational stop signal (p.Leu2Profs*12) in the TRNT1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in TRNT1 are known to be pathogenic (PMID: 25193871). -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1168431515; hg19: chr3-3170725;