chr16-89649495-G-C

Variant names:

• chr16-89649495-G-C
• NM_002768.5:c.108C>G
• CHMP1A p.Ala36Ala

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM2 PM5 BP4_Moderate

The NM_001083314.4(CHMP1A):​c.88C>G​(p.Pro30Ala) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 6/7 in silico tools predict a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. 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. P30S) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CHMP1A NM_001083314.4 missense, splice_region
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0720
• 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: Orphanet, G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-89649495-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 520606.
• BP4: Computational evidence support a benign effect (REVEL=0.179).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001083314.4. 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
	CHMP1A	NM_002768.5	MANE Select	c.108C>G	p.Ala36Ala	splice_region synonymous	Exon 4 of 7	NP_002759.2	Q9HD42-1
	CHMP1A	NM_001083314.4		c.88C>G	p.Pro30Ala	missense splice_region	Exon 3 of 6	NP_001076783.1
	CHMP1A	NR_046418.3		n.228C>G		splice_region non_coding_transcript_exon	Exon 4 of 7

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHMP1A	ENST00000397901.8	TSL:1 MANE Select	c.108C>G	p.Ala36Ala	splice_region synonymous	Exon 4 of 7	ENSP00000380998.3	Q9HD42-1
	CHMP1A	ENST00000675536.1		c.163C>G	p.Pro55Ala	missense	Exon 4 of 7	ENSP00000501759.1	A0A6Q8PFF8
	CHMP1A	ENST00000674799.1		c.-85C>G		splice_region	Exon 4 of 7	ENSP00000502267.1	A0A6Q8PFX8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.44
CADD	Benign	9.2
DANN	Benign	0.92
PhyloP100		-0.072
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr16-89715903;