18-79973765-C-A

Position:

• chr18-79973765-C-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_006701.5(TXNL4A):​c.349G>T​(p.Glu117Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000274 in 1,461,894 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 Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: TXNL4A NM_006701.5 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3 O:1
• Conservation: PhyloP100: 6.73

Genes affected

TXNL4A (HGNC:30551): (thioredoxin like 4A) The protein encoded by this gene is a member of the U5 small ribonucleoprotein particle (snRNP), and is involved in pre-mRNA splicing. This protein contains a thioredoxin-like fold and it is expected to interact with multiple proteins. Protein-protein interactions have been observed with the polyglutamine tract-binding protein 1 (PQBP1). Mutations in both the coding region and promoter region of this gene have been associated with Burn-McKeown syndrome, which is a rare disorder characterized by craniofacial dysmorphisms, cardiac defects, hearing loss, and bilateral choanal atresia. A pseudogene of this gene is found on chromosome 2. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2015]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.186 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 18-79973765-C-A is Pathogenic according to our data. Variant chr18-79973765-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 162204.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr18-79973765-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TXNL4A	NM_006701.5	c.349G>T	p.Glu117Ter	stop_gained	3/3	ENST00000269601.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TXNL4A	ENST00000269601.10	c.349G>T	p.Glu117Ter	stop_gained	3/3	1	NM_006701.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461894 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

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: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Choanal atresia-hearing loss-cardiac defects-craniofacial dysmorphism syndrome Pathogenic:2 Other:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Feb 25, 2022	- -
not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Dec 04, 2014	- -

TXNL4A-related disorder Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Apr 28, 2023

The TXNL4A c.349G>T variant is predicted to result in premature protein termination (p.Glu117*). This variant was reported in the compound heterozygous state in two siblings with Burn-McKeown syndrome (Wieczorek et al 2014. PubMed ID: 25434003; Wieczorek D et al 2003. PubMed ID: 14564154). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. Nonsense variants in TXNL4A are expected to be pathogenic. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D;D;D;D
Vest4		0.28
GERP RS		5.6
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

LitVar

Other links and lift over

dbSNP: rs727502793; hg19: chr18-77733765;