rs1555475529

Positions:

• chr16-682407-AG-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The ENST00000219548.9(STUB1):​c.832del​(p.Glu278AsnfsTer9) variant causes a frameshift change. The variant allele was found at a frequency of 0.000000684 in 1,461,044 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. Q277Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: STUB1 ENST00000219548.9 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 4.15

Genes affected

STUB1 (HGNC:11427): (STIP1 homology and U-box containing protein 1) This gene encodes a protein containing tetratricopeptide repeat and a U-box that functions as a ubiquitin ligase/cochaperone. The encoded protein binds to and ubiquitinates shock cognate 71 kDa protein (Hspa8) and DNA polymerase beta (Polb), among other targets. Mutations in this gene cause spinocerebellar ataxia, autosomal recessive 16. Alternative splicing results in multiple transcript variants. There is a pseudogene for this gene on chromosome 2. [provided by RefSeq, Jun 2014]

JMJD8 (HGNC:14148): (jumonji domain containing 8) Involved in several processes, including positive regulation of I-kappaB kinase/NF-kappaB signaling; positive regulation of sprouting angiogenesis; and regulation of glycolytic process. Located in endoplasmic reticulum lumen and nucleus. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0888 CDS is truncated, and there are 3 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-682407-AG-A is Pathogenic according to our data. Variant chr16-682407-AG-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 436890.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
STUB1	NM_005861.4	c.832del	p.Glu278AsnfsTer9	frameshift_variant	7/7	ENST00000219548.9	NP_005852.2
JMJD8	NM_001005920.4	c.*386del		3_prime_UTR_variant	9/9	ENST00000609261.6	NP_001005920.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
STUB1	ENST00000219548.9	c.832del	p.Glu278AsnfsTer9	frameshift_variant	7/7	1	NM_005861.4	ENSP00000219548	P1
JMJD8	ENST00000609261.6	c.*386del		3_prime_UTR_variant	9/9	1	NM_001005920.4	ENSP00000477481	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461044 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 726814

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

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 13, 2024

This sequence change creates a premature translational stop signal (p.Glu278Asnfs*9) in the STUB1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 26 amino acid(s) of the STUB1 protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with autosomal dominant cerebellar ataxia (PMID: 34565360, 34906452). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 436890). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this premature translational stop signal affects STUB1 function (PMID: 34565360). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

May 01, 2017

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs1555475529; hg19: chr16-732407;