3-129466891-C-T

Variant summary

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

The NM_052989.3(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). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000040 ( 0 hom. )

Consequence

IFT122
NM_052989.3 stop_gained, splice_region

Scores

3
3
1
Splicing: ADA: 0.1214
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

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]

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: {Likely_pathogenic=1, Uncertain_significance=1, Pathogenic=2}. Variant chr3-129466891-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IFT122NM_052989.3 linkc.565C>T p.Arg189* stop_gained, splice_region_variant Exon 8 of 30 ENST00000348417.7 NP_443715.1 Q9HBG6-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IFT122ENST00000348417.7 linkc.565C>T p.Arg189* stop_gained, splice_region_variant Exon 8 of 30 1 NM_052989.3 ENSP00000324005.4 Q9HBG6-1

Frequencies

GnomAD3 genomes
AF:
0.0000854
AC:
13
AN:
152184
Hom.:
0
Cov.:
33
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:
13
AN:
251482
Hom.:
0
AF XY:
0.0000441
AC XY:
6
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:
58
AN:
1461332
Hom.:
0
Cov.:
32
AF XY:
0.0000344
AC XY:
25
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:
13
AN:
152184
Hom.:
0
Cov.:
33
AF XY:
0.0000673
AC XY:
5
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.:
0
Bravo
AF:
0.000151
ESP6500AA
AF:
0.000454
AC:
2
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000576
AC:
7
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000119

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Cranioectodermal dysplasia 1 Pathogenic:3
Jun 10, 2024
Fulgent Genetics, Fulgent Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Sep 29, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. -

Dec 19, 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.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. -

IFT122-related disorder Pathogenic:1
Jul 28, 2024
PreventionGenetics, part of Exact Sciences
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

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
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
37
DANN
Uncertain
1.0
Eigen
Pathogenic
0.71
Eigen_PC
Uncertain
0.56
FATHMM_MKL
Uncertain
0.78
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.

Other links and lift over

dbSNP: rs138329739; hg19: chr3-129185734; API