NM_020806.5:c.49G>A

Variant names:

• chr14-66508576-G-A
• rs550187024
• NM_020806.5:c.49G>A

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_Moderate BP6 BS2

The NM_020806.5(GPHN):​c.49G>A​(p.Val17Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000297 in 1,614,010 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000031 (2 hom.)
• Consequence: GPHN NM_020806.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 7.07

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]

ENSG00000258561 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -7 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.06856698).
• BP6: Variant 14-66508576-G-A is Benign according to our data. Variant chr14-66508576-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1448942.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.
• BS2: High Homozygotes in GnomAdExome4 at 2 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GPHN	NM_020806.5	c.49G>A	p.Val17Ile	missense_variant	Exon 1 of 23	ENST00000478722.6	NP_065857.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GPHN	ENST00000478722.6	c.49G>A	p.Val17Ile	missense_variant	Exon 1 of 23	1	NM_020806.5	ENSP00000417901.1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152252 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000620

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000477 AC: 12 AN: 251434 AF XY: 0.0000736

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000308 AC: 45 AN: 1461640 Hom.: 2 Cov.: 30 AF XY: 0.0000481 AC XY: 35 AN XY: 727146

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.000452 AC: 39 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111806

Other (OTH) AF: 0.0000828 AC: 5 AN: 60382

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152370 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74516

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41594

American (AMR) AF: 0.00 AC: 0 AN: 15312

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5180

South Asian (SAS) AF: 0.000621 AC: 3 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2116

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000034), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000741 AC: 9

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Sulfite oxidase deficiency due to molybdenum cofactor deficiency type C Uncertain:1

Apr 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 17 of the GPHN protein (p.Val17Ile). This variant is present in population databases (rs550187024, gnomAD 0.04%), including at least one homozygous and/or hemizygous individual. 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: 1448942). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt GPHN protein function with a negative predictive value of 80%. 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. -

Inborn genetic diseases Benign:1

Mar 14, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.21
CADD	Uncertain	26
DANN	Uncertain	0.98
DEOGEN2	Benign	0.22	T;.;.;T
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Benign	0.024	T
MetaRNN	Benign	0.069	T;T;T;T
MetaSVM	Benign	-0.88	T
MutationAssessor	Benign	0.59	N;N;.;.
PrimateAI	Uncertain	0.76	T
PROVEAN	Benign	-0.46	N;N;N;N
REVEL	Benign	0.16
Sift	Benign	0.33	T;T;T;T
Sift4G	Benign	0.20	T;T;T;T
Polyphen		0.28	B;P;D;D
Vest4		0.32
MutPred		0.41		Gain of catalytic residue at D12 (P = 0.0021);Gain of catalytic residue at D12 (P = 0.0021);Gain of catalytic residue at D12 (P = 0.0021);Gain of catalytic residue at D12 (P = 0.0021);
MVP		0.19
MPC		0.52
ClinPred		0.39	T
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.28
gMVP		0.50
Mutation Taster		=76/24	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs550187024; hg19: chr14-66975294;