rs1947917811

Variant names:

• chr3-121770373-A-C
• rs1947917811
• NM_001023570.4:c.1769T>G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_001023570.4(IQCB1):​c.1769T>G​(p.Leu590*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: IQCB1 NM_001023570.4 stop_gained
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.57
• Publications: 0 publications found

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):

• ciliopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Senior-Loken syndrome 5

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• Leber congenital amaurosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Senior-Loken syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0156 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001023570.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IQCB1	NM_001023570.4	MANE Select	c.1769T>G	p.Leu590*	stop_gained	Exon 15 of 15	NP_001018864.2	Q15051-1
	IQCB1	NM_001319107.2		c.1769T>G	p.Leu590*	stop_gained	Exon 15 of 15	NP_001306036.1	Q15051-1
	IQCB1	NM_001023571.4		c.1370T>G	p.Leu457*	stop_gained	Exon 12 of 12	NP_001018865.2	Q15051-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IQCB1	ENST00000310864.11	TSL:1 MANE Select	c.1769T>G	p.Leu590*	stop_gained	Exon 15 of 15	ENSP00000311505.6	Q15051-1
	IQCB1	ENST00000349820.10	TSL:1	c.1370T>G	p.Leu457*	stop_gained	Exon 12 of 12	ENSP00000323756.7	Q15051-2
	IQCB1	ENST00000923631.1		c.1841T>G	p.Leu614*	stop_gained	Exon 16 of 16	ENSP00000593690.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Nephronophthisis (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	38
DANN	Uncertain	0.99
Eigen	Pathogenic	0.77
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		6.6
Vest4		0.28
GERP RS		5.5
Mutation Taster		=26/174	disease causing

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

Other links and lift over

dbSNP: rs1947917811; hg19: chr3-121489220;