14-66924290-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP3

The NM_020806.5(GPHN):c.826C>T(p.Arg276Trp) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000268 in 1,564,284 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

GPHN
NM_020806.5 missense, splice_region

Scores

Splicing: ADA: 0.9972

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 5.43

Variant links:

Genes affected

GPHN (HGNC:15465): (gephyrin) This gene encodes a neuronal assembly protein that anchors inhibitory neurotransmitter receptors to the postsynaptic cytoskeleton via high affinity binding to a receptor subunit domain and tubulin dimers. In nonneuronal tissues, the encoded protein is also required for molybdenum cofactor biosynthesis. Mutations in this gene may be associated with the neurological condition hyperplexia and also lead to molybdenum cofactor deficiency. Numerous alternatively spliced transcript variants encoding different isoforms have been described; however, the full-length nature of all transcript variants is not currently known. [provided by RefSeq, Jul 2008]

GPHN links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GPHN	NM_020806.5 link	c.826C>T	p.Arg276Trp	missense_variant, splice_region_variant	Exon 8 of 23	ENST00000478722.6	NP_065857.1	Q9NQX3-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GPHN	ENST00000478722.6 link	c.826C>T	p.Arg276Trp	missense_variant, splice_region_variant	Exon 8 of 23	1	NM_020806.5	ENSP00000417901.1		Q9NQX3-2

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152096

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000239

AC:

AN:

250918

Hom.:

AF XY:

0.0000295

AC XY:

AN XY:

135596

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000580

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000255

AC:

AN:

1412188

Hom.:

Cov.:

AF XY:

0.0000241

AC XY:

AN XY:

705570

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000673

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000235

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000262

Gnomad4 OTH exome

AF:

0.0000511

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152096

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74292

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000302

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Sulfite oxidase deficiency due to molybdenum cofactor deficiency type C;C4551954:Hyperekplexia 1

Uncertain:1

Sep 13, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases

Uncertain:1

Oct 01, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.826C>T (p.R276W) alteration is located in exon 8 (coding exon 8) of the GPHN gene. This alteration results from a C to T substitution at nucleotide position 826, causing the arginine (R) at amino acid position 276 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Sulfite oxidase deficiency due to molybdenum cofactor deficiency type C

Uncertain:1

Jan 25, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 276 of the GPHN protein (p.Arg276Trp). This variant is present in population databases (rs777009433, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with GPHN-related conditions. ClinVar contains an entry for this variant (Variation ID: 578563). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant¬†is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.19

BayesDel_noAF

Benign

-0.33

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.27

Eigen_PC

Uncertain

0.41

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.94

D;D

M_CAP

Benign

0.0042

MetaRNN

Benign

0.18

T;T

MetaSVM

Benign

-0.99

PrimateAI

Uncertain

0.49

PROVEAN

Benign

-0.61

N;N

REVEL

Benign

0.12

Sift

Benign

0.048

D;D

Sift4G

Benign

0.15

T;D

Polyphen

0.95

P;P

Vest4

0.27

MutPred

0.31

.;Gain of catalytic residue at D256 (P = 0.0021);

MVP

0.13

MPC

0.75

ClinPred

0.77

GERP RS

5.4

gMVP

0.50

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.76

SpliceAI score (max)

0.060

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over