16-89647238-C-A

Variant names:

• chr16-89647238-C-A
• rs1064794609
• NM_002768.5:c.346G>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_002768.5(CHMP1A):​c.346G>T​(p.Glu116*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,609,146 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CHMP1A NM_002768.5 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.38
• Publications: 0 publications found

Genes affected

CHMP1A (HGNC:8740): (charged multivesicular body protein 1A) This gene encodes a member of the CHMP/Chmp family of proteins which are involved in multivesicular body sorting of proteins to the interiors of lysosomes. The initial prediction of the protein sequence encoded by this gene suggested that the encoded protein was a metallopeptidase. The nomenclature has been updated recently to reflect the correct biological function of this encoded protein. Several transcripts encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2012]

CHMP1A Gene-Disease associations (from GenCC):

• pontocerebellar hypoplasia type 8

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, PanelApp Australia, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002768.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHMP1A	NM_002768.5	MANE Select	c.346G>T	p.Glu116*	stop_gained	Exon 5 of 7	NP_002759.2
	CHMP1A	NM_001083314.4		c.326G>T	p.Arg109Leu	missense	Exon 4 of 6	NP_001076783.1
	CHMP1A	NR_046418.3		n.466G>T		non_coding_transcript_exon	Exon 5 of 7

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHMP1A	ENST00000397901.8	TSL:1 MANE Select	c.346G>T	p.Glu116*	stop_gained	Exon 5 of 7	ENSP00000380998.3
	CHMP1A	ENST00000547687.2	TSL:1	n.606G>T		non_coding_transcript_exon	Exon 1 of 2
	CHMP1A	ENST00000535997.7	TSL:2	c.346G>T	p.Glu116*	stop_gained	Exon 5 of 7	ENSP00000442120.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152216 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1456930 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 724306

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33418

American (AMR) AF: 0.00 AC: 0 AN: 44014

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25926

East Asian (EAS) AF: 0.00 AC: 0 AN: 39542

South Asian (SAS) AF: 0.0000117 AC: 1 AN: 85158

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52758

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110168

Other (OTH) AF: 0.00 AC: 0 AN: 60182

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152216 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74344

African (AFR) AF: 0.00 AC: 0 AN: 41456

American (AMR) AF: 0.00 AC: 0 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5188

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68036

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	42
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		7.4
Vest4		0.94
ClinPred		0.99	D
GERP RS		4.5

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: rs1064794609; hg19: chr16-89713646;