chr16-1583365-CG-C

Position:

• chr16-1583365-CG-C

Variant summary

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

The NM_014714.4(IFT140):​c.1380del​(p.Asn460LysfsTer28) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: IFT140 NM_014714.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 0.216

Genes affected

IFT140 (HGNC:29077): (intraflagellar transport 140) This gene encodes one of the subunits of the intraflagellar transport (IFT) complex A. Intraflagellar transport is involved in the genesis, resorption and signaling of primary cilia. The primary cilium is a microtubule-based sensory organelle at the surface of most quiescent mammalian cells, that receives signals from its environment, such as the flow of fluid, light or odors, and transduces those signals to the nucleus. Loss of the corresponding protein in mouse results in renal cystic disease. [provided by RefSeq, Jun 2012]

(HGNC:):

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 16-1583365-CG-C is Pathogenic according to our data. Variant chr16-1583365-CG-C is described in ClinVar as [Pathogenic]. Clinvar id is 97055.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IFT140	NM_014714.4	c.1380del	p.Asn460LysfsTer28	frameshift_variant	12/31	ENST00000426508.7	NP_055529.2
LOC105371046	NR_135176.1	n.59+2781del		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IFT140	ENST00000426508.7	c.1380del	p.Asn460LysfsTer28	frameshift_variant	12/31	5	NM_014714.4	ENSP00000406012	P1
	ENST00000563162.1	n.59+2781del		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251220 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135800

Gnomad AFR exome AF: 0.00

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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Short-rib thoracic dysplasia without polydactyly Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

May 01, 2013

- -

Saldino-Mainzer syndrome;C4540439:Retinitis pigmentosa 80 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

May 17, 2022

- -

Saldino-Mainzer syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 09, 2022

This sequence change creates a premature translational stop signal (p.Asn460Lysfs*28) in the IFT140 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in IFT140 are known to be pathogenic (PMID: 22503633, 23418020, 24009529, 26216056). This variant is present in population databases (rs431905522, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with asphyxiating thoracic dystrophy (PMID: 23418020). ClinVar contains an entry for this variant (Variation ID: 97055). For these reasons, this variant has been classified as Pathogenic. -

Renal cyst Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Oct 10, 2024

Based on the classification scheme VCGS_Germline_v1.3.5, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with retinitis pigmentosa 80 (MIM#617781), short-rib thoracic dysplasia 9 with or without polydactyly (MIM#266920) and cystic kidney disease (MONDO:0002473), IFT140-related (PMID: 34890546). (I) 0108 - This gene is associated with both recessive and dominant disease. Retinitis pigmentosa 80 (MIM#617781) and short-rib thoracic dysplasia 9 with or without polydactyly (MIM#266920) are inherited in an autosomal recessive manner, while cystic kidney disease (MONDO:0002473), IFT140-related is inherited in an autosomal dominant manner (OMIM, PMID: 34890546). (I) 0112 - The dominant condition associated with this gene may have incomplete penetrance. Parents of children with short-rib thoracic dysplasia 9 with or without polydactyly, who carry a single pathogenic variant that has also previously been associated with the dominant cystic kidney disease phenotype, have been reported as unaffected (PMID: 34890546). However, these parents weren't specifically assessed for cystic kidney disease. (I) 0201 - Variant is predicted to cause nonsense-mediated decay (NMD) and loss of protein (premature termination codon is located at least 54 nucleotides upstream of the final exon-exon junction). (SP) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD <0.01 (v2: 1 heterozygote, 0 homozygotes). (SP) 0701 - Other NMD-predicted variants comparable to the one identified in this case have very strong previous evidence for pathogenicity (DECIPHER). These variants have been reported in families with later onset autosomal dominant polycystic kidney disease (PMID: 34890546) and autosomal recessive IFT140-related conditions (PMIDs: 22503633, 26968735). (SP) 0802 - This variant has moderate previous evidence of pathogenicity in unrelated individuals. It has been observed in a compound heterozygous individual with Jeune asphyxiating thoracic dystrophy with severe kidney involvement and retinal disease (PMID: 23418020). In addition, it has been reported as pathogenic by two clinical laboratories (ClinVar). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
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

Other links and lift over

dbSNP: rs431905522; hg19: chr16-1633366;