17-80215120-C-T

Position:

• chr17-80215120-C-T

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PS1_Very_Strong PM2 PP3_Strong PP5_Very_Strong

The NM_000199.5(SGSH):​c.268G>A​(p.Gly90Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000343 in 1,459,448 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin ClinVar. Synonymous variant affecting the same amino acid position (i.e. G90G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: SGSH NM_000199.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 7.54

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]

CARD14 (HGNC:16446): (caspase recruitment domain family member 14) This gene encodes a caspase recruitment domain-containing protein that is a member of the membrane-associated guanylate kinase (MAGUK) family of proteins. Members of this protein family are scaffold proteins that are involved in a diverse array of cellular processes including cellular adhesion, signal transduction and cell polarity control. This protein has been shown to specifically interact with BCL10, a protein known to function as a positive regulator of cell apoptosis and NF-kappaB activation. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Apr 2012]

ACMG classification

Verdict is Pathogenic. Variant got 22 ACMG points.

• PS1: Transcript NM_000199.5 (SGSH) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar as 1066348
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988
• PP5: Variant 17-80215120-C-T is Pathogenic according to our data. Variant chr17-80215120-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 550542.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SGSH	NM_000199.5	c.268G>A	p.Gly90Arg	missense_variant	3/8	ENST00000326317.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SGSH	ENST00000326317.11	c.268G>A	p.Gly90Arg	missense_variant	3/8	1	NM_000199.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000804 AC: 2 AN: 248612 Hom.: 0 AF XY: 0.00000741 AC XY: 1 AN XY: 134960

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000545

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000888

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000343 AC: 5 AN: 1459448 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726130

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000825 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Mucopolysaccharidosis, MPS-III-A Pathogenic:5

Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Feb 01, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Nov 15, 2019	Variant summary: SGSH c.268G>A (p.Gly90Arg) results in a non-conservative amino acid change located in the Sulfatase, N-terminal domain of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 248612 control chromosomes (gnomAD). c.268G>A has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type IIIA (Sanfilippo Syndrome A)(Bunge_1997, Sun_2011, Heron_2011, Chistiakov_2014). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. A ClinVar submission (evaluation after 2014) cites the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jan 15, 2024	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Sep 08, 2023	This variant is present in population databases (rs774010006, gnomAD 0.006%). This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 90 of the SGSH protein (p.Gly90Arg). This missense change has been observed in individual(s) with clinical features of SGSH-related conditions (PMID: 21204211, 21455105, 24875751). ClinVar contains an entry for this variant (Variation ID: 550542). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SGSH protein function. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.82	D;T;.
Eigen	Pathogenic	0.75
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D;D
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.4	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-7.1	D;.;.
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D;.;.
Sift4G	Uncertain	0.047	D;.;.
Polyphen		1.0	D;.;.
Vest4		0.94
MutPred		0.94		Gain of catalytic residue at G90 (P = 0.0096);.;Gain of catalytic residue at G90 (P = 0.0096);
MVP		0.97
MPC		0.80
ClinPred		1.0	D
GERP RS		3.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.98
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs774010006; hg19: chr17-78188919;