X-38352777-A-C

Position:

• chrX-38352777-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP5 BP4

The NM_000531.6(OTC):​c.77+4A>C variant causes a splice donor region, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 23)
• Consequence: OTC NM_000531.6 splice_donor_region, intron
• Scores: Splicing: ADA: 0.7143
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 4.73

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-38352777-A-C is Pathogenic according to our data. Variant chrX-38352777-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 97316.Status of the report is no_assertion_criteria_provided, 0 stars.
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.41). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
OTC	NM_000531.6	c.77+4A>C		splice_donor_region_variant, intron_variant		ENST00000039007.5
OTC	NM_001407092.1	c.77+4A>C		splice_donor_region_variant, intron_variant
OTC	XM_017029556.2	c.77+4A>C		splice_donor_region_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
OTC	ENST00000039007.5	c.77+4A>C		splice_donor_region_variant, intron_variant		1	NM_000531.6	P1
OTC	ENST00000643344.1	c.77+4A>C		splice_donor_region_variant, intron_variant, NMD_transcript_variant
OTC	ENST00000488812.1	n.169+4A>C		splice_donor_region_variant, intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 25

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

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.41
CADD	Benign	22
DANN	Benign	0.95

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.71
dbscSNV1_RF	Benign	0.51
SpliceAI score (max)		0.010		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: rs72552301; hg19: chrX-38212030;