8-90995771-C-A

Variant names:

• chr8-90995771-C-A
• NM_018710.3:c.680G>T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_018710.3(PIP4P2):​c.680G>T​(p.Trp227Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,468 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PIP4P2 NM_018710.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.50

Genes affected

PIP4P2 (HGNC:25452): (phosphatidylinositol-4,5-bisphosphate 4-phosphatase 2) TMEM55A catalyzes the degradation of phosphatidylinositol 4,5-bisphosphate (PtdIns-4,5-P2) by removing the 4-phosphate (Ungewickell et al., 2005 [PubMed 16365287]).[supplied by OMIM, Mar 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.943

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIP4P2	NM_018710.3	c.680G>T	p.Trp227Leu	missense_variant	Exon 7 of 7	ENST00000285419.8	NP_061180.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIP4P2	ENST00000285419.8	c.680G>T	p.Trp227Leu	missense_variant	Exon 7 of 7	1	NM_018710.3	ENSP00000285419.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460468 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726504

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000253

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Mar 10, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.680G>T (p.W227L) alteration is located in exon 7 (coding exon 7) of the TMEM55A gene. This alteration results from a G to T substitution at nucleotide position 680, causing the tryptophan (W) at amino acid position 227 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.76
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Benign	0.25	T;T
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.91	D;D
M_CAP	Benign	0.013	T
MetaRNN	Pathogenic	0.94	D;D
MetaSVM	Benign	-0.33	T
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-8.3	D;D
REVEL	Uncertain	0.48
Sift	Uncertain	0.0040	D;D
Sift4G	Uncertain	0.032	D;.
Polyphen		0.98	D;.
Vest4		0.77
MutPred		0.84		Loss of catalytic residue at W227 (P = 0.0537);.;
MVP		0.66
MPC		1.4
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.86
gMVP		0.94

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr8-92007999; COSMIC: COSV99575212; COSMIC: COSV99575212;