Genetic Variant CHIA:p.Met1? (chr1-111315282-G-A) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PVS1_SupportingPM2

The NM_021797.4(CHIA):c.3G>A(p.Met1?) variant causes a start lost change. The variant allele was found at a frequency of 0.0000136 in 1,611,978 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

CHIA
NM_021797.4 start_lost

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.82

Variant links:

Genes affected

CHIA (HGNC:17432): (chitinase acidic) The protein encoded by this gene degrades chitin, which is found in the cell wall of most fungi as well as in arthropods and some nematodes. The encoded protein can also stimulate interleukin 13 expression, and variations in this gene can lead to asthma susceptibility. Several transcript variants encoding a few different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]

CHIA links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PVS1

Start lost variant, no pathogenic variants between lost start and next in-frame start position. Next in-frame start position is after 54 codons. Genomic position: 111317684. Lost 0.145 part of the original CDS.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHIA	NM_201653.4 link	c.327G>A	p.Met109Ile	missense_variant	Exon 6 of 12	ENST00000369740.6	NP_970615.2	Q9BZP6-1A8K3T7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHIA	ENST00000369740.6 link	c.327G>A	p.Met109Ile	missense_variant	Exon 6 of 12	1	NM_201653.4	ENSP00000358755.1		Q9BZP6-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152100

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000199

AC:

AN:

251196

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135740

show subpopulations

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:

0.000163

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000137

AC:

AN:

1459878

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

726270

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000209

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152100

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74294

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

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:

0.0000329

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jan 02, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.327G>A (p.M109I) alteration is located in exon 6 (coding exon 5) of the CHIA gene. This alteration results from a G to A substitution at nucleotide position 327, causing the methionine (M) at amino acid position 109 to be replaced by an isoleucine (I). 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

Uncertain

0.54

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Benign

-0.28

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.25

.;T;T;.

Eigen

Uncertain

0.48

Eigen_PC

Uncertain

0.50

FATHMM_MKL

Uncertain

0.97

LIST_S2

Uncertain

0.95

D;.;D;D

M_CAP

Benign

0.018

MetaRNN

Benign

0.32

T;T;T;T

MetaSVM

Benign

-1.2

MutationAssessor

Uncertain

2.5

.;M;M;.

PrimateAI

Benign

0.37

PROVEAN

Uncertain

-3.8

D;D;D;D

REVEL

Benign

0.13

Sift

Benign

0.092

T;D;D;D

Sift4G

Uncertain

0.040

D;T;T;D

Polyphen

0.50

.;P;P;.

Vest4

0.65, 0.65, 0.82

MutPred

0.69

.;Gain of catalytic residue at M109 (P = 0.0126);Gain of catalytic residue at M109 (P = 0.0126);.;

MVP

0.29

MPC

0.12

ClinPred

0.96

GERP RS

4.7

Varity_R

0.92

gMVP

0.80

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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