9-98078196-G-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 4P and 8B. PM2PM5BP4_StrongBS1

The NM_018946.4(NANS):c.452G>T(p.Arg151Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000743 in 1,614,132 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R151H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00041 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000040 ( 0 hom. )

Consequence

NANS
NM_018946.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:1

Conservation

PhyloP100: 9.53

Variant links:

Genes affected

NANS (HGNC:19237): (N-acetylneuraminate synthase) This gene encodes an enzyme that functions in the biosynthetic pathways of sialic acids. In vitro, the encoded protein uses N-acetylmannosamine 6-phosphate and mannose 6-phosphate as substrates to generate phosphorylated forms of N-acetylneuraminic acid (Neu5Ac) and 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN), respectively; however, it exhibits much higher activity toward the Neu5Ac phosphate product. In insect cells, expression of this gene results in Neu5Ac and KDN production. This gene is related to the E. coli sialic acid synthase gene neuB, and it can partially restore sialic acid synthase activity in an E. coli neuB-negative mutant. [provided by RefSeq, Jul 2008]

NANS links:

TRIM14 (HGNC:16283): (tripartite motif containing 14) The protein encoded by this gene is a member of the tripartite motif (TRIM) family. The TRIM motif includes three zinc-binding domains, a RING, a B-box type 1 and a B-box type 2, and a coiled-coil region. The protein localizes to cytoplasmic bodies and its function has not been determined. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2010]

TRIM14 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr9-98078196-G-A is described in Lovd as [Likely_pathogenic].

BP4

Computational evidence support a benign effect (MetaRNN=0.025363594).

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000407 (62/152262) while in subpopulation AFR AF= 0.00149 (62/41550). AF 95% confidence interval is 0.00119. There are 0 homozygotes in gnomad4. There are 31 alleles in male gnomad4 subpopulation. Median coverage is 31. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NANS	NM_018946.4 linkuse as main transcript	c.452G>T	p.Arg151Leu	missense_variant	4/6	ENST00000210444.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NANS	ENST00000210444.6 linkuse as main transcript	c.452G>T	p.Arg151Leu	missense_variant	4/6	1	NM_018946.4	P1

Frequencies

GnomAD3 genomes

AF:

0.000421

AC:

AN:

152144

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00154

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000127

AC:

AN:

251448

Hom.:

AF XY:

0.000110

AC XY:

AN XY:

135894

show subpopulations

Gnomad AFR exome

AF:

0.00197

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000397

AC:

AN:

1461870

Hom.:

Cov.:

AF XY:

0.0000413

AC XY:

AN XY:

727232

show subpopulations

Gnomad4 AFR exome

AF:

0.00167

Gnomad4 AMR exome

AF:

0.0000224

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:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.000407

AC:

AN:

152262

Hom.:

Cov.:

AF XY:

0.000416

AC XY:

AN XY:

74450

show subpopulations

Gnomad4 AFR

AF:

0.00149

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000240

Hom.:

Bravo

AF:

0.000499

ESP6500AA

AF:

0.000908

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000148

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 19, 2022

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 151 of the NANS protein (p.Arg151Leu). This variant is present in population databases (rs140402727, gnomAD 0.2%). This variant has not been reported in the literature in individuals affected with NANS-related conditions. ClinVar contains an entry for this variant (Variation ID: 1432466). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest 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. -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 03, 2022

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

0.28

BayesDel_addAF

Benign

-0.086

BayesDel_noAF

Uncertain

0.10

Cadd

Uncertain

Dann

Benign

0.92

DEOGEN2

Benign

0.0016

T;T

Eigen

Benign

0.079

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.91

D;D

M_CAP

Benign

0.024

MetaRNN

Benign

0.025

T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

0.95

L;.

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.77

PROVEAN

Benign

-0.030

N;N

REVEL

Uncertain

0.32

Sift

Benign

1.0

T;D

Sift4G

Benign

0.69

T;D

Polyphen

0.0020

B;.

Vest4

0.91

MVP

0.55

MPC

0.28

ClinPred

0.16

GERP RS

5.3

Varity_R

0.39

gMVP

0.84

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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