3-129466891-C-T

Position:

chr3-129466891-C-T

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1PM2PP5

The ENST00000348417.7(IFT122):c.565C>T(p.Arg189*) variant causes a stop gained, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000044 in 1,613,516 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. R189R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000040 ( 0 hom. )

Consequence

IFT122
ENST00000348417.7 stop_gained, splice_region

Scores

Splicing: ADA: 0.1214

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:1

Conservation

PhyloP100: 0.962

Variant links:

Genes affected

IFT122 (HGNC:13556): (intraflagellar transport 122) This gene encodes a member of the WD repeat protein family. WD repeats are minimally conserved regions of approximately 40 amino acids typically bracketed by gly-his and trp-asp (GH-WD), which may facilitate formation of heterotrimeric or multiprotein complexes. Members of this family are involved in a variety of cellular processes, including cell cycle progression, signal transduction, apoptosis, and gene regulation. This cytoplasmic protein contains seven WD repeats and an AF-2 domain which function by recruiting coregulatory molecules and in transcriptional activation. Mutations in this gene cause cranioectodermal dysplasia-1. A related pseudogene is located on chromosome 3. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2013]

IFT122 links:

IFT122 (HGNC:):

IFT122 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 3-129466891-C-T is Pathogenic according to our data. Variant chr3-129466891-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 581786.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=2, Uncertain_significance=1}. Variant chr3-129466891-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IFT122	NM_052989.3 linkuse as main transcript	c.565C>T	p.Arg189*	stop_gained, splice_region_variant	8/30	ENST00000348417.7	NP_443715.1	Q9HBG6-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IFT122	ENST00000348417.7 linkuse as main transcript	c.565C>T	p.Arg189*	stop_gained, splice_region_variant	8/30	1	NM_052989.3	ENSP00000324005.4		Q9HBG6-1

Frequencies

GnomAD3 genomes

AF:

0.0000854

AC:

AN:

152184

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000314

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:

0.0000517

AC:

AN:

251482

Hom.:

AF XY:

0.0000441

AC XY:

AN XY:

135914

show subpopulations

Gnomad AFR exome

AF:

0.000369

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:

0.0000615

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000397

AC:

AN:

1461332

Hom.:

Cov.:

AF XY:

0.0000344

AC XY:

AN XY:

727032

show subpopulations

Gnomad4 AFR exome

AF:

0.000269

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000387

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000854

AC:

AN:

152184

Hom.:

Cov.:

AF XY:

0.0000673

AC XY:

AN XY:

74334

show subpopulations

Gnomad4 AFR

AF:

0.000314

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:

0.0000462

Hom.:

Bravo

AF:

0.000151

ESP6500AA

AF:

0.000454

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000576

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Cranioectodermal dysplasia 1

Pathogenic:2Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 29, 2023	Variant summary: IFT122 c.718C>T (p.Arg240X) results in a premature termination codon, predicted to cause absence of the protein due to nonsense mediated decay, a commonly known mechanism for disease. The variant allele was found at a frequency of 5.2e-05 in 251482 control chromosomes (gnomAD). To our knowledge, no occurrence of c.718C>T in individuals affected with Cranioectodermal Dysplasia 1 and no experimental evidence demonstrating its impact on protein function have been reported. Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. One submitter classified the variant as pathogenic, and one submitter classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jul 31, 2022	This sequence change creates a premature translational stop signal (p.Arg240*) in the IFT122 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in IFT122 are known to be pathogenic (PMID: 20493458, 23826986, 26792575). This variant is present in population databases (rs138329739, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with IFT122-related conditions. ClinVar contains an entry for this variant (Variation ID: 581786). For these reasons, this variant has been classified as Pathogenic. -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Aug 29, 2017	The IFT122 c.718C>T (p.Arg240Ter) variant is a stop-gained variant, which was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018) and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score for this variant, it could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change. No publications were found based on this search. Due to the potential impact of stop-gained variants and the lack of clarifying evidence, this variant is classified as a variant of unknown significance but suspicious for pathogenicity for cranioectodermal dysplasia. -

IFT122-related disorder

Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jul 28, 2024

The IFT122 c.718C>T variant is predicted to result in premature protein termination (p.Arg240*). This variant has not been reported in an individual with IFT122 related disease. This variant is reported in 0.028% of alleles in individuals of African descent in gnomAD. Nonsense variants in IFT122 are expected to be pathogenic. This variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.40

BayesDel_noAF

Pathogenic

0.58

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.71

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Uncertain

0.78

MutationTaster

Benign

1.0

A;A;A;D;D;D;D;D

Vest4

0.25

GERP RS

4.6

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.12

dbscSNV1_RF

Benign

0.60

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

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