19-13105551-C-A

Position:

• chr19-13105551-C-A

Variant summary

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

The NM_001136035.4(TRMT1):​c.1639G>T​(p.Gly547*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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: 32)
• Consequence: TRMT1 NM_001136035.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 2.83

Genes affected

TRMT1 (HGNC:25980): (tRNA methyltransferase 1) This gene encodes a tRNA-modifying enzyme that acts as a dimethyltransferase, modifying a single guanine residue at position 26 of the tRNA. The encoded enzyme has both mono- and dimethylase activity when exogenously expressed, and uses S-adenosyl methionine as a methyl donor. The C-terminal region of the encoded protein has both a zinc finger motif, and an arginine/proline-rich region. Mutations in this gene have been implicated in autosomal recessive intellectual disorder (ARID). Alternative splicing results in multiple transcript variants encoding different isoforms. There is a pseudogene of this gene on the X chromosome. [provided by RefSeq, May 2017]

TRMT1 (HGNC:):

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 19-13105551-C-A is Pathogenic according to our data. Variant chr19-13105551-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 3063891.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TRMT1	NM_001136035.4	c.1639G>T	p.Gly547*	stop_gained	15/17	ENST00000357720.9	NP_001129507.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TRMT1	ENST00000357720.9	c.1639G>T	p.Gly547*	stop_gained	15/17	2	NM_001136035.4	ENSP00000350352.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Intellectual developmental disorder, autosomal recessive 68 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jan 12, 2024

Variant summary: TRMT1 c.1639G>T (p.Gly547X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 251084 control chromosomes. To our knowledge, no occurrence of c.1639G>T in individuals affected with Intellectual Developmental Disorder, Autosomal Recessive 68 and no experimental evidence demonstrating its impact on protein function have been reported. No submitters have cited clinical-significance assessments for this variant to ClinVar. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	37
DANN	Uncertain	0.99
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.46
FATHMM_MKL	Uncertain	0.80	D
Vest4		0.25
GERP RS		3.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr19-13216365;