18-11852051-G-C

Variant names:

• chr18-11852051-G-C
• rs141531709
• NM_020412.5:c.540G>C

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_020412.5(CHMP1B):​c.540G>C​(p.Val180Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,272 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. V180V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CHMP1B NM_020412.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0660
• 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: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.43).
• BP7: Synonymous conserved (PhyloP=-0.066 with no splicing effect.

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.540G>C	p.Val180Val	synonymous	Exon 1 of 1	NP_065145.2
	GNAL	NM_182978.4	MANE Select	c.723-10344G>C		intron	N/A	NP_892023.1	P38405-2
	GNAL	NM_001369387.1	MANE Plus Clinical	c.492-10344G>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.540G>C	p.Val180Val	synonymous	Exon 1 of 1	ENSP00000432279.1	Q7LBR1
	GNAL	ENST00000334049.11	TSL:1 MANE Select	c.723-10344G>C		intron	N/A	ENSP00000334051.5	P38405-2
	GNAL	ENST00000423027.8	TSL:1 MANE Plus Clinical	c.492-10344G>C		intron	N/A	ENSP00000408489.2	P38405-1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461272 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726938

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44644

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26108

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 86216

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53286

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5756

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111762

Other (OTH) AF: 0.00 AC: 0 AN: 60338

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.43
CADD	Benign	7.5
DANN	Benign	0.84
PhyloP100		-0.066

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: rs141531709; hg19: chr18-11852050;