2-27470947-ACT-ACTCT

Position:

• chr2-27470947-ACT-ACTCT

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_015662.3(IFT172):​c.1671_1672dupAG​(p.Val558fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000138 in 1,454,268 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: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: IFT172 NM_015662.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 3.35

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]

IFT172 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 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 2-27470947-A-ACT is Pathogenic according to our data. Variant chr2-27470947-A-ACT is described in ClinVar as [Pathogenic]. Clinvar id is 97029.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IFT172	NM_015662.3	c.1671_1672dupAG	p.Val558fs	frameshift_variant	16/48	ENST00000260570.8	NP_056477.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IFT172	ENST00000260570.8	c.1671_1672dupAG	p.Val558fs	frameshift_variant	16/48	1	NM_015662.3	ENSP00000260570.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1454268 Hom.: 0 Cov.: 30 AF XY: 0.00000276 AC XY: 2 AN XY: 723410

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

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

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 10, 2022

This sequence change creates a premature translational stop signal (p.Val558Glufs*12) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with asphyxiating thoracic dystrophy (PMID: 24140113). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Short-rib thoracic dysplasia 10 with polydactyly Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 07, 2013

- -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs587777083; hg19: chr2-27693814;