rs373909351

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_001023570.4(IQCB1):​c.1465C>T​(p.Arg489*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000446 in 1,614,054 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000048 ( 0 hom. )

Consequence

IQCB1
NM_001023570.4 stop_gained

Scores

2
4
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 3.66
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 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. There are 12 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 3-121772659-G-A is Pathogenic according to our data. Variant chr3-121772659-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 30778.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-121772659-G-A is described in Lovd as [Likely_pathogenic]. Variant chr3-121772659-G-A is described in Lovd as [Pathogenic]. Variant chr3-121772659-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IQCB1NM_001023570.4 linkc.1465C>T p.Arg489* stop_gained Exon 14 of 15 ENST00000310864.11 NP_001018864.2 Q15051-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IQCB1ENST00000310864.11 linkc.1465C>T p.Arg489* stop_gained Exon 14 of 15 1 NM_001023570.4 ENSP00000311505.6 Q15051-1
IQCB1ENST00000349820.10 linkc.1066C>T p.Arg356* stop_gained Exon 11 of 12 1 ENSP00000323756.7 Q15051-2
IQCB1ENST00000393650.7 linkn.*443C>T non_coding_transcript_exon_variant Exon 13 of 14 5 ENSP00000377261.3 Q15051-3
IQCB1ENST00000393650.7 linkn.*443C>T 3_prime_UTR_variant Exon 13 of 14 5 ENSP00000377261.3 Q15051-3

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152208
Hom.:
0
Cov.:
32
show subpopulations
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000278
AC:
7
AN:
251408
Hom.:
0
AF XY:
0.0000294
AC XY:
4
AN XY:
135874
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000479
AC:
70
AN:
1461846
Hom.:
0
Cov.:
32
AF XY:
0.0000426
AC XY:
31
AN XY:
727226
show subpopulations
Gnomad4 AFR exome
AF:
0.0000896
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000580
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000522
Gnomad4 OTH exome
AF:
0.0000497
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152208
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74352
show subpopulations
Gnomad4 AFR
AF:
0.00
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:
0.0000294
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000236
Hom.:
0
Bravo
AF:
0.0000302
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Senior-Loken syndrome 5 Pathogenic:7
-
Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: research

A known stop-gain variant, c.1465C>T in exon 14 of IQCB1 was identified in a homozygous state in the proband (Halbritter et al, 2013). Sanger validation and segregation showed that the variant was present in a homozygous state in the proband and heterozygous state in her parents. The variant is present in 72 individuals in a heterozygous state and absent in a homozygous state in gnomAD (v4.1.0). The variant is absent in homozygous and/or heterozygous state our in-house database of 3274 exomes. This variant is predicted to introduce a premature termination codon which will either cause the transcript to undergo nonsense-mediated mRNA decay or lead to formation of a truncated protein product. -

May 23, 2017
Undiagnosed Diseases Network, NIH
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The maternally-inherited c.1465C>T is a nonsense variant, which is predicted to result in loss of function in the IQCB1 gene where loss of function is a known mechanism of Senior-Loken syndrome 5, MIM 609254. The c.1465C>T variant was observed to be in trans with a c.1518_1519delCA pathogenic variant based on segregation analysis in the family. Both variants are also also present in the patient's similarly affected sister. -

Jan 01, 2011
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

Mar 04, 2024
Fulgent Genetics, Fulgent Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jan 01, 2024
Daryl Scott Lab, Baylor College of Medicine
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

PVS1, PS4, PM3 -

May 28, 2019
Mendelics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 08, 2024
Baylor Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Retinal dystrophy Pathogenic:2
Jan 01, 2017
Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 24, 2017
Blueprint Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nephronophthisis Pathogenic:1
Sep 18, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg489*) in the IQCB1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in IQCB1 are known to be pathogenic (PMID: 15723066, 21901789, 23559409, 28041643). This variant is present in population databases (rs373909351, gnomAD 0.007%). This premature translational stop signal has been observed in individual(s) with autosomal recessive Leber congenital amaurosis and early onset retinitis pigmentosa (PMID: 18076122, 20881296, 21220633, 23847139, 24066033, 29053603). This variant is also known as c.1381C>T, Arg461*. ClinVar contains an entry for this variant (Variation ID: 30778). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.49
D
BayesDel_noAF
Pathogenic
0.51
CADD
Pathogenic
43
DANN
Uncertain
1.0
Eigen
Uncertain
0.51
Eigen_PC
Uncertain
0.32
FATHMM_MKL
Uncertain
0.88
D
Vest4
0.23
GERP RS
4.1

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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.

Other links and lift over

dbSNP: rs373909351; hg19: chr3-121491506; API