Genetic Variant XIST:n.12167G>T (chrX-73827734-C-A) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The ENST00000429829.6(XIST):n.12167G>T variant causes a non coding transcript exon change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: not found (cov: 23)

Exomes 𝑓: 0.0 ( 0 hom. 0 hem. )

Failed GnomAD Quality Control

Consequence

XIST
ENST00000429829.6 non_coding_transcript_exon

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -0.423

Variant links:

Genes affected

XIST (HGNC:12810): (X inactive specific transcript) X inactivation is an early developmental process in mammalian females that transcriptionally silences one of the pair of X chromosomes, thus providing dosage equivalence between males and females. The process is regulated by several factors, including a region of chromosome X called the X inactivation center (XIC). The XIC comprises several non-coding and protein-coding genes, and this gene was the first non-coding gene identified within the XIC. This gene is expressed exclusively from the XIC of the inactive X chromosome, and is essential for the initiation and spread of X-inactivation. The transcript is a spliced RNA. Alternatively spliced transcript variants have been identified, but their full length sequences have not been determined. Mutations in the XIST promoter cause familial skewed X inactivation. [provided by RefSeq, Apr 2012]

XIST links:

TSIX (HGNC:12377): (TSIX transcript, XIST antisense RNA) In mammals, dosage compensation of genes on the X chromosome occurs by X inactivation, which is regulated in cis by the X-inactivation center (XIC) and expression of the XIST non-coding RNA. This gene expresses a non-coding antisense transcript across the 3' end of the XIST locus, and is coexpressed with XIST only from the inactive X chromosome. The mouse ortholog of this locus is required for imprinted X inactivation in extraembryonic tissues and silences Xist through modification of the chromatin structure in the Xist promoter region. In contrast, imprinted X inactivation does not occur in human extraembryonic tissues and transcripts from this locus do not repress XIST expression or affect random X chromosome inactivation in embryonic cells. This transcript is thought to be unspliced and extend over more than 30 kb, but its exact nature has not been determined. [provided by RefSeq, Jul 2008]

TSIX links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.58).

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	Exon rank
XIST	NR_001564.3 link	n.12158G>T	non_coding_transcript_exon_variant	Exon 6 of 6
TSIX	NR_003255.2 link	n.35530C>A	non_coding_transcript_exon_variant	Exon 1 of 1
XIST	NR_190997.1 link	n.12158G>T	non_coding_transcript_exon_variant	Exon 6 of 8

Ensembl

Gene	Transcript	HGVSc	Effect	Exon rank	TSL
XIST	ENST00000429829.6 link	n.12167G>T	non_coding_transcript_exon_variant	Exon 6 of 6	1
XIST	ENST00000421322.3 link	n.1339G>T	non_coding_transcript_exon_variant	Exon 6 of 7	2
XIST	ENST00000433732.2 link	n.450G>T	non_coding_transcript_exon_variant	Exon 3 of 3	2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

435773

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

160451

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.58

CADD

Benign

5.5

DANN

Benign

0.81

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

0.97

Splicing

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

Publications

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Computational scores

Splicing

Publications

Other links and lift over