rs121918175

Positions:

• chr7-65974923-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_000181.4(GUSB):​c.1061C>T​(p.Ala354Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000821 in 1,461,326 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: GUSB NM_000181.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 4.53

Genes affected

GUSB (HGNC:4696): (glucuronidase beta) This gene encodes a hydrolase that degrades glycosaminoglycans, including heparan sulfate, dermatan sulfate, and chondroitin-4,6-sulfate. The enzyme forms a homotetramer that is localized to the lysosome. Mutations in this gene result in mucopolysaccharidosis type VII. Alternative splicing results in multiple transcript variants. There are many pseudogenes of this locus in the human genome.[provided by RefSeq, May 2014]

GUSB (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983
• PP5: Variant 7-65974923-G-A is Pathogenic according to our data. Variant chr7-65974923-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 896.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}. Variant chr7-65974923-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GUSB	NM_000181.4	c.1061C>T	p.Ala354Val	missense_variant	6/12	ENST00000304895.9	NP_000172.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GUSB	ENST00000304895.9	c.1061C>T	p.Ala354Val	missense_variant	6/12	1	NM_000181.4	ENSP00000302728.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251142 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135740

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000821 AC: 12 AN: 1461326 Hom.: 0 Cov.: 32 AF XY: 0.0000138 AC XY: 10 AN XY: 726972

Gnomad4 AFR exome AF: 0.0000598

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Mucopolysaccharidosis type 7 Pathogenic:1 Uncertain:1

Pathogenic, no assertion criteria provided	literature only	OMIM	Jan 01, 1993	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Apr 07, 2022	This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 354 of the GUSB protein (p.Ala354Val). This variant is present in population databases (rs121918175, gnomAD 0.006%). This missense change has been observed in individual(s) with mucopolysaccharidosis type VII (PMID: 8111413). ClinVar contains an entry for this variant (Variation ID: 896). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Experimental studies have shown that this missense change affects GUSB function (PMID: 8111413). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jan 04, 2023

Published functional studies demonstrate a damaging effect on residual enzymatic activity (PMID: 8111413).; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 19224584, 8111413, 6811712) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.37
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Pathogenic	0.17
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D;.
Eigen	Uncertain	0.56
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Benign	0.79	T;T
M_CAP	Pathogenic	0.40	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.4	M;.
PrimateAI	Benign	0.47	T
PROVEAN	Uncertain	-2.7	D;N
REVEL	Uncertain	0.63
Sift	Uncertain	0.013	D;D
Sift4G	Uncertain	0.029	D;D
Polyphen		0.99	D;.
Vest4		0.81
MutPred		0.86		Loss of ubiquitination at K350 (P = 0.0648);.;
MVP		0.97
MPC		1.1
ClinPred		0.93	D
GERP RS		5.1
Varity_R		0.53
gMVP		0.81

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs121918175; hg19: chr7-65439910;