chr16-1557968-T-A

Variant names:

• chr16-1557968-T-A
• rs1555486589
• NM_014714.4:c.2366A>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_014714.4(IFT140):​c.2366A>T​(p.Asp789Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. D789D) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: IFT140 NM_014714.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.73
• Publications: 0 publications found

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]

IFT140 Gene-Disease associations (from GenCC):

• autosomal dominant polycystic kidney disease

  Inheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics, ClinGen
• IFT140-related recessive ciliopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Illumina
• short-rib thoracic dysplasia 9 with or without polydactyly

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet
• retinitis pigmentosa 80

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Leber congenital amaurosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Jeune syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.855

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IFT140	NM_014714.4	c.2366A>T	p.Asp789Val	missense_variant	Exon 19 of 31	ENST00000426508.7	NP_055529.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IFT140	ENST00000426508.7	c.2366A>T	p.Asp789Val	missense_variant	Exon 19 of 31	5	NM_014714.4	ENSP00000406012.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Saldino-Mainzer syndrome Uncertain:1

Feb 10, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with valine, which is neutral and non-polar, at codon 789 of the IFT140 protein (p.Asp789Val). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with IFT140-related conditions. ClinVar contains an entry for this variant (Variation ID: 465315). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.30
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Benign	0.37	T
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Uncertain	0.18	D
MutationAssessor	Pathogenic	3.3	M
PhyloP100		7.7
PrimateAI	Uncertain	0.54	T
PROVEAN	Pathogenic	-7.9	D
REVEL	Uncertain	0.56
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.86
MutPred		0.36		Gain of helix (P = 0.0696);
MVP		0.90
MPC		0.48
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.82
gMVP		0.84
Mutation Taster		=27/73	disease causing

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

Other links and lift over

dbSNP: rs1555486589; hg19: chr16-1607969;