X-68048432-C-A

Position:

• chrX-68048432-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_002547.3(OPHN1):​c.2401G>T​(p.Glu801Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000274 in 1,096,755 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 1 hemizygotes in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 0.0000027 (0 hom. 1 hem.)
• Consequence: OPHN1 NM_002547.3 stop_gained
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.17

Genes affected

OPHN1 (HGNC:8148): (oligophrenin 1) This gene encodes a Rho-GTPase-activating protein that promotes GTP hydrolysis of Rho subfamily members. Rho proteins are important mediators of intracellular signal transduction, which affects cell migration and cell morphogenesis. Mutations in this gene are responsible for OPHN1-related X-linked cognitive disability with cerebellar hypoplasia and distinctive facial dysmorhphism. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.00332 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
OPHN1	NM_002547.3	c.2401G>T	p.Glu801Ter	stop_gained	24/25	ENST00000355520.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
OPHN1	ENST00000355520.6	c.2401G>T	p.Glu801Ter	stop_gained	24/25	1	NM_002547.3	P1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD3 exomes AF: 0.00000548 AC: 1 AN: 182546 Hom.: 0 AF XY: 0.0000149 AC XY: 1 AN XY: 67144

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000123

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 3 AN: 1096755 Hom.: 0 Cov.: 28 AF XY: 0.00000276 AC XY: 1 AN XY: 362195

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: 0.00000357

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Feb 14, 2023

Nonsense variant predicted to result in protein truncation as the last 2 amino acids are lost, although loss-of-function variants have not been reported downstream of this position in the protein; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	39
DANN	Uncertain	1.0
FATHMM_MKL	Uncertain	0.91	D
MutationTaster	Benign	0.63	N;N
Vest4		0.61
GERP RS		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.18		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: rs1338314674; hg19: chrX-67268274;