rs72558422

Positions:

• chrX-38403720-C-CT

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_000531.6(OTC):​c.645dup​(p.Gln216SerfsTer9) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 23)
• Consequence: OTC NM_000531.6 frameshift
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.63

Genes affected

OTC (HGNC:8512): (ornithine transcarbamylase) This nuclear gene encodes a mitochondrial matrix enzyme. The encoded protein is involved in the urea cycle which functions to detoxify ammonia into urea for excretion. Mutations in this enzyme lead to ornithine transcarbamylase deficiency, which causes hyperammonemia. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Pathogenic. Variant got 11 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 X-38403720-C-CT is Pathogenic according to our data. Variant chrX-38403720-C-CT is described in ClinVar as [Pathogenic]. Clinvar id is 97279.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
OTC	NM_000531.6	c.645dup	p.Gln216SerfsTer9	frameshift_variant	6/10	ENST00000039007.5
OTC	NM_001407092.1	c.645dup	p.Gln216SerfsTer9	frameshift_variant	8/12
OTC	XM_017029556.2	c.645dup	p.Gln216SerfsTer9	frameshift_variant	6/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
OTC	ENST00000039007.5	c.645dup	p.Gln216SerfsTer9	frameshift_variant	6/10	1	NM_000531.6	P1
OTC	ENST00000643344.1	c.*395dup		3_prime_UTR_variant, NMD_transcript_variant	7/11

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

GenMed Metabolism Lab

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Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs72558422; hg19: chrX-38262973;