2-208326358-C-T

Variant names:

• chr2-208326358-C-T
• rs1529979
• NM_015040.4:c.3547C>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_015040.4(PIKFYVE):​c.3547C>T​(p.Gln1183*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: PIKFYVE NM_015040.4 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.40
• Publications: 32 publications found

Genes affected

PIKFYVE (HGNC:23785): (phosphoinositide kinase, FYVE-type zinc finger containing) Phosphorylated derivatives of phosphatidylinositol (PtdIns) regulate cytoskeletal functions, membrane trafficking, and receptor signaling by recruiting protein complexes to cell- and endosomal-membranes. Humans have multiple PtdIns proteins that differ by the degree and position of phosphorylation of the inositol ring. This gene encodes an enzyme (PIKfyve; also known as phosphatidylinositol-3-phosphate 5-kinase type III or PIPKIII) that phosphorylates the D-5 position in PtdIns and phosphatidylinositol-3-phosphate (PtdIns3P) to make PtdIns5P and PtdIns(3,5)biphosphate. The D-5 position also can be phosphorylated by type I PtdIns4P-5-kinases (PIP5Ks) that are encoded by distinct genes and preferentially phosphorylate D-4 phosphorylated PtdIns. In contrast, PIKfyve preferentially phosphorylates D-3 phosphorylated PtdIns. In addition to being a lipid kinase, PIKfyve also has protein kinase activity. PIKfyve regulates endomembrane homeostasis and plays a role in the biogenesis of endosome carrier vesicles from early endosomes. The protein plays a key role in cell entry of ebola virus and SARS-CoV-2 by endocytosis Mutations in this gene cause corneal fleck dystrophy (CFD); an autosomal dominant disorder characterized by numerous small white flecks present in all layers of the corneal stroma. Histologically, these flecks appear to be keratocytes distended with lipid and mucopolysaccharide filled intracytoplasmic vacuoles. [provided by RefSeq, Jul 2021]

PIKFYVE Gene-Disease associations (from GenCC):

• fleck corneal dystrophy

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015040.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIKFYVE	NM_015040.4	MANE Select	c.3547C>T	p.Gln1183*	stop_gained	Exon 20 of 42	NP_055855.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIKFYVE	ENST00000264380.9	TSL:1 MANE Select	c.3547C>T	p.Gln1183*	stop_gained	Exon 20 of 42	ENSP00000264380.4
	PIKFYVE	ENST00000909798.1		c.3562C>T	p.Gln1188*	stop_gained	Exon 21 of 43	ENSP00000579857.1
	PIKFYVE	ENST00000923116.1		c.3529C>T	p.Gln1177*	stop_gained	Exon 20 of 42	ENSP00000593175.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 62

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Uncertain	0.67
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.90	D
PhyloP100		4.4
Vest4		0.73
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=4/196	disease causing (fs/PTC)

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: rs1529979; hg19: chr2-209191082;