18-11851696-C-G

Variant names:

• chr18-11851696-C-G
• rs201261255
• NM_020412.5:c.185C>G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_020412.5(CHMP1B):​c.185C>G​(p.Ala62Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,692 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CHMP1B NM_020412.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.10

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)

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.12050393).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHMP1B	NM_020412.5	c.185C>G	p.Ala62Gly	missense_variant	Exon 1 of 1	ENST00000526991.3	NP_065145.2
GNAL	NM_182978.4	c.723-10699C>G		intron_variant	Intron 5 of 11	ENST00000334049.11	NP_892023.1
GNAL	NM_001369387.1	c.492-10699C>G		intron_variant	Intron 5 of 11	ENST00000423027.8	NP_001356316.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHMP1B	ENST00000526991.3	c.185C>G	p.Ala62Gly	missense_variant	Exon 1 of 1	6	NM_020412.5	ENSP00000432279.1
GNAL	ENST00000334049.11	c.723-10699C>G		intron_variant	Intron 5 of 11	1	NM_182978.4	ENSP00000334051.5
GNAL	ENST00000423027.8	c.492-10699C>G		intron_variant	Intron 5 of 11	1	NM_001369387.1	ENSP00000408489.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461692 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727130

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.085
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.49
CADD	Benign	18
DANN	Benign	0.95
DEOGEN2	Benign	0.26	T
Eigen	Benign	-0.64
Eigen_PC	Benign	-0.52
FATHMM_MKL	Benign	0.044	N
LIST_S2	Benign	0.82	T
M_CAP	Benign	0.015	T
MetaRNN	Benign	0.12	T
MetaSVM	Benign	-0.90	T
PrimateAI	Benign	0.48	T
PROVEAN	Benign	-0.58	N
REVEL	Benign	0.10
Sift	Benign	0.59	T
Sift4G	Benign	0.41	T
Polyphen		0.0030	B
Vest4		0.061
MutPred		0.38		Loss of methylation at R67 (P = 0.1565);
MVP		0.65
MPC		0.60
ClinPred		0.12	T
GERP RS		1.3
Varity_R		0.068
gMVP		0.43

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

Other links and lift over

dbSNP: rs201261255; hg19: chr18-11851695;