NM_001177701.3:c.466G>T

Variant names:

• chr22-36758406-C-A
• rs1472758160
• NM_001177701.3:c.466G>T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_001177701.3(IFT27):​c.466G>T​(p.Glu156*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000137 in 1,460,852 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: IFT27 NM_001177701.3 stop_gained
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.01

Genes affected

IFT27 (HGNC:18626): (intraflagellar transport 27) This gene encodes a GTP-binding protein that is a core component of the intraflagellar transport complex B. Characterization of the similar Chlamydomonas protein indicates a function in cell cycle control. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Jan 2012]

CACNG2-DT (HGNC:55682): (CACNG2 divergent transcript)

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 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 0.169 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IFT27	NM_001177701.3	c.466G>T	p.Glu156*	stop_gained	Exon 7 of 7	ENST00000433985.7	NP_001171172.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IFT27	ENST00000433985.7	c.466G>T	p.Glu156*	stop_gained	Exon 7 of 7	1	NM_001177701.3	ENSP00000393541.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251448 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135904

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.00000137 AC: 2 AN: 1460852 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 726824

Gnomad4 AFR exome AF: 0.00

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 Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Dec 11, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change results in a premature translational stop signal in the IFT27 gene (p.Glu155*). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 31 amino acids of the IFT27 protein. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with IFT27-related conditions. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Uncertain	0.89	D
Vest4		0.32
GERP RS		4.4

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.20		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.20		Position offset: -3

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1472758160; hg19: chr22-37154450;