chr18-11851642-A-C

Variant names:

• chr18-11851642-A-C
• rs759848382
• NM_020412.5:c.131A>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_020412.5(CHMP1B):​c.131A>C​(p.Asn44Thr) variant causes a missense 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. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N44S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CHMP1B NM_020412.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.12
• Publications: 0 publications found

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]

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]

CHMP1B-AS1 (HGNC:52778): (CHMP1B antisense RNA 1)

ENSG00000296678 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.931

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020412.5. 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
	CHMP1B	NM_020412.5	MANE Select	c.131A>C	p.Asn44Thr	missense	Exon 1 of 1	NP_065145.2
	GNAL	NM_182978.4	MANE Select	c.723-10753A>C		intron	N/A	NP_892023.1	P38405-2
	GNAL	NM_001369387.1	MANE Plus Clinical	c.492-10753A>C		intron	N/A	NP_001356316.1	A8K1Y9

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHMP1B	ENST00000526991.3	TSL:6 MANE Select	c.131A>C	p.Asn44Thr	missense	Exon 1 of 1	ENSP00000432279.1	Q7LBR1
	GNAL	ENST00000334049.11	TSL:1 MANE Select	c.723-10753A>C		intron	N/A	ENSP00000334051.5	P38405-2
	GNAL	ENST00000423027.8	TSL:1 MANE Plus Clinical	c.492-10753A>C		intron	N/A	ENSP00000408489.2	P38405-1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.52
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Benign	-0.090
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	D
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Benign	0.62	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.93	D
MetaSVM	Uncertain	0.64	D
PhyloP100		7.1
PrimateAI	Pathogenic	0.79	T
PROVEAN	Pathogenic	-5.8	D
REVEL	Pathogenic	0.76
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0040	D
Polyphen		1.0	D
Vest4		0.81
MutPred		0.76		Loss of loop (P = 0.1258)
MVP		0.86
MPC		1.6
ClinPred		0.99	D
GERP RS		5.5
PromoterAI		-0.061	Neutral
Varity_R		0.68
gMVP		0.69

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: rs759848382; hg19: chr18-11851641;