8-81659398-C-T

Position:

chr8-81659398-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4

The NM_005536.4(IMPA1):c.787G>A(p.Ala263Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,612,144 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

IMPA1
NM_005536.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.01

Variant links:

Genes affected

IMPA1 (HGNC:6050): (inositol monophosphatase 1) This gene encodes an enzyme that dephosphorylates myo-inositol monophosphate to generate free myo-inositol, a precursor of phosphatidylinositol, and is therefore an important modulator of intracellular signal transduction via the production of the second messengers myoinositol 1,4,5-trisphosphate and diacylglycerol. This enzyme can also use myo-inositol-1,3-diphosphate, myo-inositol-1,4-diphosphate, scyllo-inositol-phosphate, glucose-1-phosphate, glucose-6-phosphate, fructose-1-phosphate, beta-glycerophosphate, and 2'-AMP as substrates. This enzyme shows magnesium-dependent phosphatase activity and is inhibited by therapeutic concentrations of lithium. Inhibition of inositol monophosphate hydroylosis and subsequent depletion of inositol for phosphatidylinositol synthesis may explain the anti-manic and anti-depressive effects of lithium administered to treat bipolar disorder. Alternative splicing results in multiple transcript variants encoding distinct isoforms. A pseudogene of this gene is also present on chromosome 8q21.13. [provided by RefSeq, Dec 2014]

IMPA1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.30292803).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
IMPA1	NM_005536.4 linkuse as main transcript	c.787G>A	p.Ala263Thr	missense_variant	9/9	ENST00000256108.10	NP_005527.1
IMPA1	NM_001144878.2 linkuse as main transcript	c.964G>A	p.Ala322Thr	missense_variant	10/10		NP_001138350.1
IMPA1	NM_001144879.2 linkuse as main transcript	c.*81G>A		3_prime_UTR_variant	8/8		NP_001138351.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IMPA1	ENST00000256108.10 linkuse as main transcript	c.787G>A	p.Ala263Thr	missense_variant	9/9	1	NM_005536.4	ENSP00000256108	P1	P29218-1
IMPA1	ENST00000449740.6 linkuse as main transcript	c.964G>A	p.Ala322Thr	missense_variant	10/10	1		ENSP00000408526		P29218-3
IMPA1	ENST00000311489.8 linkuse as main transcript	c.*81G>A		3_prime_UTR_variant	8/8	2		ENSP00000311803		P29218-2

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152170

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000120

AC:

AN:

250974

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135672

show subpopulations

Gnomad AFR exome

AF:

0.000123

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:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1459974

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726372

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000671

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:

0.00

Gnomad4 OTH exome

AF:

0.0000663

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152170

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74340

show subpopulations

Gnomad4 AFR

AF:

0.0000965

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000659

Hom.:

Bravo

AF:

0.0000378

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 23, 2024

The c.964G>A (p.A322T) alteration is located in exon 10 (coding exon 9) of the IMPA1 gene. This alteration results from a G to A substitution at nucleotide position 964, causing the alanine (A) at amino acid position 322 to be replaced by a threonine (T). 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

Benign

0.19

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.33

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.37

T;.

Eigen

Uncertain

0.45

Eigen_PC

Uncertain

0.43

FATHMM_MKL

Uncertain

0.88

LIST_S2

Uncertain

0.91

D;D

M_CAP

Benign

0.028

MetaRNN

Benign

0.30

T;T

MetaSVM

Benign

-0.67

MutationAssessor

Benign

1.8

L;.

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Benign

0.44

PROVEAN

Benign

-1.7

N;N

REVEL

Benign

0.24

Sift

Benign

0.075

T;D

Sift4G

Benign

0.14

T;T

Polyphen

0.96

D;.

Vest4

0.34

MVP

0.82

MPC

0.35

ClinPred

0.50

GERP RS

5.0

Varity_R

0.33

gMVP

0.53

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over