18-11851907-G-A

Position:

chr18-11851907-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_020412.5(CHMP1B):c.396G>A(p.Met132Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,826 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

CHMP1B
NM_020412.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.60

Variant links:

Genes affected

CHMP1B (HGNC:24287): (charged multivesicular body protein 1B) CHMP1B belongs to the chromatin-modifying protein/charged multivesicular body protein (CHMP) family. These proteins are components of ESCRT-III (endosomal sorting complex required for transport III), a complex involved in degradation of surface receptor proteins and formation of endocytic multivesicular bodies (MVBs). Some CHMPs have both nuclear and cytoplasmic/vesicular distributions, and one such CHMP, CHMP1A (MIM 164010), is required for both MVB formation and regulation of cell cycle progression (Tsang et al., 2006 [PubMed 16730941]).[supplied by OMIM, Mar 2008]

CHMP1B links:

GNAL (HGNC:4388): (G protein subunit alpha L) This gene encodes a stimulatory G protein alpha subunit which mediates odorant signaling in the olfactory epithelium. This protein couples dopamine type 1 receptors and adenosine A2A receptors and is widely expressed in the central nervous system. Mutations in this gene have been associated with dystonia 25 and this gene is located in a susceptibility region for bipolar disorder and schizophrenia. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2013]

GNAL links:

CHMP1B-AS1 (HGNC:):

CHMP1B-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHMP1B	NM_020412.5 linkuse as main transcript	c.396G>A	p.Met132Ile	missense_variant	1/1	ENST00000526991.3	NP_065145.2	Q7LBR1
GNAL	NM_182978.4 linkuse as main transcript	c.723-10488G>A		intron_variant		ENST00000334049.11	NP_892023.1	P38405-2
GNAL	NM_001369387.1 linkuse as main transcript	c.492-10488G>A		intron_variant		ENST00000423027.8	NP_001356316.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	UniProt
CHMP1B	ENST00000526991.3 linkuse as main transcript	c.396G>A	p.Met132Ile	missense_variant	1/1	6	NM_020412.5	ENSP00000432279.1	Q7LBR1
GNAL	ENST00000334049.11 linkuse as main transcript	c.723-10488G>A		intron_variant		1	NM_182978.4	ENSP00000334051.5	P38405-2
GNAL	ENST00000423027.8 linkuse as main transcript	c.492-10488G>A		intron_variant		1	NM_001369387.1	ENSP00000408489.2	P38405-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152172

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.00000401

AC:

AN:

249166

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135184

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000885

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461654

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727110

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

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:

8.99e-7

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152172

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74340

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

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

Bravo

AF:

0.0000340

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

Dec 18, 2023

The c.396G>A (p.M132I) alteration is located in exon 1 (coding exon 1) of the CHMP1B gene. This alteration results from a G to A substitution at nucleotide position 396, causing the methionine (M) at amino acid position 132 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

Pathogenic

0.89

BayesDel_addAF

Pathogenic

0.19

BayesDel_noAF

Uncertain

0.040

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.55

Eigen

Pathogenic

0.72

Eigen_PC

Pathogenic

0.71

FATHMM_MKL

Uncertain

0.78

LIST_S2

Uncertain

0.97

M_CAP

Benign

0.062

MetaRNN

Uncertain

0.73

MetaSVM

Uncertain

0.013

PrimateAI

Uncertain

0.76

PROVEAN

Uncertain

-3.5

REVEL

Uncertain

0.50

Sift

Benign

0.046

Sift4G

Benign

0.084

Polyphen

0.71

Vest4

0.70

MutPred

0.54

Loss of loop (P = 0.1258);

MVP

0.92

MPC

1.4

ClinPred

0.97

GERP RS

5.6

Varity_R

0.60

gMVP

0.74

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