17-80220226-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000199.5(SGSH):​c.88G>T​(p.Ala30Ser) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000022 in 1,366,088 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000022 ( 0 hom. )

Consequence

SGSH
NM_000199.5 missense, splice_region

Scores

3
9
7
Splicing: ADA: 1.000
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.900
Variant links:
Genes affected
SGSH (HGNC:10818): (N-sulfoglucosamine sulfohydrolase) This gene encodes the enzyme sulfamidase; one of several enzymes involved in the lysosomal degradation of heparan sulfate. Mutations in this gene are associated with the lysosomal storage disease mucopolysaccaridosis IIIA, also known as Sanfilippo syndrome A, which results from impaired degradation of heparan sulfate. Transcripts of varying sizes have been reported but their biological validity has not been determined. [provided by RefSeq, Jun 2017]
SLC26A11 (HGNC:14471): (solute carrier family 26 member 11) This gene encodes a member of the solute linked carrier 26 family of anion exchangers. Members of this family of proteins are essential for numerous cellular functions including homeostasis and intracellular electrolyte balance. The encoded protein is a sodium independent sulfate transporter that is sensitive to the anion exchanger inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Oct 2009]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
SGSHNM_000199.5 linkuse as main transcriptc.88G>T p.Ala30Ser missense_variant, splice_region_variant 1/8 ENST00000326317.11 NP_000190.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
SGSHENST00000326317.11 linkuse as main transcriptc.88G>T p.Ala30Ser missense_variant, splice_region_variant 1/81 NM_000199.5 ENSP00000314606 P1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD3 exomes
AF:
0.00000861
AC:
1
AN:
116146
Hom.:
0
AF XY:
0.0000156
AC XY:
1
AN XY:
63992
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000230
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000220
AC:
3
AN:
1366088
Hom.:
0
Cov.:
30
AF XY:
0.00000445
AC XY:
3
AN XY:
673732
show subpopulations
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:
0.00000280
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-III-A Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJun 22, 2022This sequence change affects codon 30 of the SGSH mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the SGSH protein. This variant also falls at the last nucleotide of exon 1, which is part of the consensus splice site for this exon. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with SGSH-related conditions. 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: "Deleterious"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C0"). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts the c.88G nucleotide in the SGSH gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 22976768, 26331342). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.18
BayesDel_addAF
Uncertain
0.13
D
BayesDel_noAF
Uncertain
-0.010
CADD
Pathogenic
33
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.64
D;.;.
Eigen
Benign
0.084
Eigen_PC
Benign
0.077
FATHMM_MKL
Uncertain
0.84
D
LIST_S2
Uncertain
0.92
D;T;D
M_CAP
Pathogenic
0.82
D
MetaRNN
Uncertain
0.60
D;T;D
MetaSVM
Pathogenic
0.83
D
MutationAssessor
Benign
1.6
L;.;.
MutationTaster
Benign
1.0
D;D;N
PrimateAI
Pathogenic
0.82
D
PROVEAN
Benign
-2.0
N;.;.
REVEL
Uncertain
0.63
Sift
Benign
0.084
T;.;.
Sift4G
Uncertain
0.012
D;D;.
Polyphen
0.37
B;.;.
Vest4
0.57
MutPred
0.52
Gain of sheet (P = 4e-04);Gain of sheet (P = 4e-04);Gain of sheet (P = 4e-04);
MVP
0.93
MPC
0.18
ClinPred
0.79
D
GERP RS
3.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.6
Varity_R
0.52
gMVP
0.81

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.95
SpliceAI score (max)
0.010
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs758793075; hg19: chr17-78194025; API