chr2-27445435-TTCTC-T

Variant names:

• chr2-27445435-TTCTC-T
• rs587777078
• NM_015662.3:c.4925_4928delGAGA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_015662.3(IFT172):​c.4925_4928delGAGA​(p.Arg1642LysfsTer32) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,611,018 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: IFT172 NM_015662.3 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.59

Genes affected

IFT172 (HGNC:30391): (intraflagellar transport 172) This gene encodes a subunit of the intraflagellar transport subcomplex IFT-B. Subcomplexes IFT-A and IFT-B are necessary for ciliary assembly and maintenance. Mutations in this gene have been associated with skeletal ciliopathies, with or without polydactyly, such as such short-rib thoracic dysplasias 1, 9 or 10. [provided by RefSeq, Mar 2014]

KRTCAP3 (HGNC:28943): (keratinocyte associated protein 3) Predicted to be integral component of membrane. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Pathogenic. Variant got 18 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 2-27445435-TTCTC-T is Pathogenic according to our data. Variant chr2-27445435-TTCTC-T is described in ClinVar as [Pathogenic]. Clinvar id is 97023.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-27445435-TTCTC-T is described in Lovd as [Pathogenic]. Variant chr2-27445435-TTCTC-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IFT172	NM_015662.3	c.4925_4928delGAGA	p.Arg1642LysfsTer32	frameshift_variant	Exon 46 of 48	ENST00000260570.8	NP_056477.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IFT172	ENST00000260570.8	c.4925_4928delGAGA	p.Arg1642LysfsTer32	frameshift_variant	Exon 46 of 48	1	NM_015662.3	ENSP00000260570.3

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 152028 Hom.: 0 Cov.: 32

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: 0.00000813 AC: 2 AN: 245956 Hom.: 0 AF XY: 0.0000150 AC XY: 2 AN XY: 132952

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000110

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: 0.00000206 AC: 3 AN: 1458990 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 725470

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 152028 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74250

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

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Short-rib thoracic dysplasia 10 without polydactyly Pathogenic:1

Nov 07, 2013

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Short-rib thoracic dysplasia 10 with or without polydactyly;C4225342:Retinitis pigmentosa 71 Pathogenic:1

Dec 04, 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.Arg1642Lysfs*32) in the IFT172 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in IFT172 are known to be pathogenic (PMID: 24140113). This variant is present in population databases (rs587777078, gnomAD 0.01%). This premature translational stop signal has been observed in individual(s) with Mainzer-Saldino syndrome (PMID: 24140113). For these reasons, this variant has been classified as Pathogenic. -

Short-rib thoracic dysplasia 10 with or without polydactyly;C4225342:Retinitis pigmentosa 71;C4310707:Bardet-Biedl syndrome 20 Pathogenic:1

May 25, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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

Other links and lift over

dbSNP: rs587777078; hg19: chr2-27668302;