rs1555538156

Positions:

• chr16-71576238-C-CA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000353.3(TAT):​c.177_178insT​(p.Val60CysfsTer33) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,212 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 32)
• Consequence: TAT NM_000353.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: -2.48

Genes affected

TAT (HGNC:11573): (tyrosine aminotransferase) This nuclear gene encodes a mitochondrial protein tyrosine aminotransferase which is present in the liver and catalyzes the conversion of L-tyrosine into p-hydroxyphenylpyruvate. Mutations in this gene cause tyrosinemia (type II, Richner-Hanhart syndrome), a disorder accompanied by major skin and corneal lesions, with possible cognitive disability. A regulator gene for tyrosine aminotransferase is X-linked. [provided by RefSeq, Jul 2008]

TAT-AS1 (HGNC:51369): (TAT antisense RNA 1)

ACMG classification

Verdict is Pathogenic. Variant got 18 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 16-71576238-C-CA is Pathogenic according to our data. Variant chr16-71576238-C-CA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 557491.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TAT	NM_000353.3	c.177_178insT	p.Val60CysfsTer33	frameshift_variant	2/12	ENST00000355962.5	NP_000344.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TAT	ENST00000355962.5	c.177_178insT	p.Val60CysfsTer33	frameshift_variant	2/12	1	NM_000353.3	ENSP00000348234	P1
TAT	ENST00000566010.1	n.273_274insT		non_coding_transcript_exon_variant	2/2	1
TAT-AS1	ENST00000561529.1	n.751-1825dup		intron_variant, non_coding_transcript_variant		5
TAT	ENST00000566094.5	n.273_274insT		non_coding_transcript_exon_variant	2/3	2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152212 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

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

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152212 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74358

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.0000654

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

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tyrosinemia type II Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 09, 2023	This sequence change creates a premature translational stop signal (p.Val60Cysfs*33) in the TAT gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in TAT are known to be pathogenic (PMID: 9544843). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with clinical features of tyrosinemia type II (PMID: 27832414). ClinVar contains an entry for this variant (Variation ID: 557491). For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Apr 02, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 28, 2024	- -

Computational scores

Source: dbNSFP v4.3

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: rs1555538156; hg19: chr16-71610141;