NM_001023570.4:c.1549A>G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001023570.4(IQCB1):c.1549A>G(p.Asn517Asp) variant causes a missense change. The variant allele was found at a frequency of 0.0000131 in 152,226 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N517Y) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Consequence

IQCB1
NM_001023570.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.90

Publications

4 publications found

Variant links:

Genes affected

IQCB1 (HGNC:28949): (IQ motif containing B1) This gene encodes a nephrocystin protein that interacts with calmodulin and the retinitis pigmentosa GTPase regulator protein. The encoded protein has a central coiled-coil region and two calmodulin-binding IQ domains. It is localized to the primary cilia of renal epithelial cells and connecting cilia of photoreceptor cells. The protein is thought to play a role in ciliary function. Defects in this gene result in Senior-Loken syndrome type 5. Alternative splicing results in multiple transcript variants. A pseudogene of this gene is found on chromosome 6. [provided by RefSeq, Jan 2016]

IQCB1 Gene-Disease associations (from GenCC):

Senior-Loken syndrome 5
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
Leber congenital amaurosis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Senior-Loken syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

IQCB1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.15485728).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IQCB1	NM_001023570.4 link	c.1549A>G	p.Asn517Asp	missense_variant	Exon 14 of 15	ENST00000310864.11	NP_001018864.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
IQCB1	ENST00000310864.11 link	c.1549A>G	p.Asn517Asp	missense_variant	Exon 14 of 15	1	NM_001023570.4	ENSP00000311505.6
IQCB1	ENST00000349820.10 link	c.1150A>G	p.Asn384Asp	missense_variant	Exon 11 of 12	1		ENSP00000323756.7
IQCB1	ENST00000393650.7 link	n.*527A>G		non_coding_transcript_exon_variant	Exon 13 of 14	5		ENSP00000377261.3
IQCB1	ENST00000393650.7 link	n.*527A>G		3_prime_UTR_variant	Exon 13 of 14	5		ENSP00000377261.3

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152226

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

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

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152226

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74376

show subpopulations

African (AFR)

AF:

0.0000482

AC:

AN:

41456

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5200

South Asian (SAS)

AF:

0.00

AC:

AN:

4838

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Nephronophthisis

Uncertain:1

Feb 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces asparagine, which is neutral and polar, with aspartic acid, which is acidic and polar, at codon 517 of the IQCB1 protein (p.Asn517Asp). This variant is present in population databases (no rsID available, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with IQCB1-related conditions. ClinVar contains an entry for this variant (Variation ID: 954309). 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 IQCB1 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

BayesDel_addAF

Benign

-0.064

BayesDel_noAF

Benign

-0.33

CADD

Benign

(source)

DANN

Benign

0.77

DEOGEN2

Benign

0.031

T;.

Eigen

Benign

-0.17

Eigen_PC

Benign

-0.081

FATHMM_MKL

Benign

0.70

LIST_S2

Benign

0.77

T;T

M_CAP

Benign

0.057

MetaRNN

Benign

0.15

T;T

MetaSVM

Benign

-0.61

MutationAssessor

Benign

1.4

L;.

PhyloP100

3.9

PrimateAI

Uncertain

0.55

PROVEAN

Benign

1.2

N;N

REVEL

Benign

0.23

Sift

Benign

1.0

T;T

Sift4G

Benign

1.0

T;T

Polyphen

0.96

P;B

Vest4

0.22

MutPred

0.27

Loss of helix (P = 0.0444);.;

MVP

0.85

MPC

0.14

ClinPred

0.38

GERP RS

5.0

Varity_R

0.054

gMVP

0.077

Mutation Taster

=87/13

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over