rs753472891

chr17-80213846-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000199.5(SGSH):c.703G>A(p.Asp235Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,608,590 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D235H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: SGSH NM_000199.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 7.40

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 16 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-80213846-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2817814.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983
• PP5: Variant 17-80213846-C-T is Pathogenic according to our data. Variant chr17-80213846-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 553004.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.703G>A	p.Asp235Asn	missense_variant	6/8	ENST00000326317.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SGSH	ENST00000326317.11	c.703G>A	p.Asp235Asn	missense_variant	6/8	1	NM_000199.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152226 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000121

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.0000168 AC: 4 AN: 237402 Hom.: 0 AF XY: 0.0000232 AC XY: 3 AN XY: 129136

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000296

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000168

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: 0.0000124 AC: 18 AN: 1456364 Hom.: 0 Cov.: 31 AF XY: 0.0000110 AC XY: 8 AN XY: 724286

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000226

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000126

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000990

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152226 Hom.: 0 Cov.: 32 AF XY: 0.0000672 AC XY: 5 AN XY: 74366

Gnomad4 AFR AF: 0.000121

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.000478

Alfa AF: 0.0000558 Hom.: 0

Bravo AF: 0.0000756

ExAC AF: 0.00000828 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Mucopolysaccharidosis, MPS-III-A Pathogenic:5

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Oct 14, 2023	- -
Likely 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	May 11, 2022	Variant summary: SGSH c.703G>A (p.Asp235Asn) results in a conservative amino acid change located in the Sulfatase, N-terminal domain (IPR000917) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.7e-05 in 237402 control chromosomes (gnomAD). c.703G>A has been reported in the literature in compound heterozygous individuals affected with Mucopolysaccharidosis Type IIIA (Sanfilippo Syndrome A) (Beesley_2000, Lee-Chen_2002, Heron_2011). These data indicate that the variant is likely to be associated with disease. A different variant affecting the same codon (Asp235Val) has been reported in affected individuals, suggesting this may be an important residue (Beesley_2000). One publication reports that the variant protein has 1.7% N-Sulphatase activity (Lee-Chen_2002). Three ClinVar submitters have assessed the variant since 2014: two classify the variant as likely pathogenic and one as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Jul 27, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Oct 22, 2023	This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 235 of the SGSH protein (p.Asp235Asn). This variant is present in population databases (rs753472891, gnomAD 0.02%). This missense change has been observed in individual(s) with mucopolysaccharidosis type III (PMID: 11182930, 12000360, 19099774; Invitae). ClinVar contains an entry for this variant (Variation ID: 553004). 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. Experimental studies have shown that this missense change affects SGSH function (PMID: 12000360). This variant disrupts the p.Asp235 amino acid residue in SGSH. Other variant(s) that disrupt this residue have been observed in individuals with SGSH-related conditions (PMID: 9401012), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

SGSH-related disorder Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Oct 13, 2022

The SGSH c.703G>A variant is predicted to result in the amino acid substitution p.Asp235Asn. This variant along with a second variant in SGSH was reported in multiple individuals with Sanfilippo syndrome IIIA (also known as Sanfilippo A) (Beesley et al. 2000. PubMed ID: 11182930; Zhang et al. 2008. PubMed ID: 19099774; Lee-Chen et al. 2002. PubMed ID: 12000360; Table S2, Héron et al. 2011. PubMed ID: 21204211; Delgadillo et al. 2013. PubMed ID: 24314109). In addition, a different variant affecting the same amino acid (p.Asp235Val) was reported to be pathogenic for Sanfilippo syndrome A (Bunge et al. 1997. PubMed ID: 9401012). Structure and computational predication studies suggest this variant disrupts enzyme activity (Sidhu et al. 2014. PubMed ID: 24816101; Ugrinov et al. 2015. PubMed ID: 25807448). This variant is reported in 0.015% of alleles in individuals of East Asian descent in gnomAD (http://gnomad.broadinstitute.org/variant/17-78187645-C-T). This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Benign	-0.022	T
BayesDel_noAF	Uncertain	0.0
Cadd	Pathogenic	29
Dann	Pathogenic	1.0
DEOGEN2	Uncertain	0.79	D
Eigen	Uncertain	0.67
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.62	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	1.4	L
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-4.0	D
REVEL	Pathogenic	0.83
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.047	D
Polyphen		1.0	D
Vest4		0.88
MutPred		0.87		Gain of loop (P = 0.0312);
MVP		0.98
MPC		0.75
ClinPred		0.91	D
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.93
gMVP		0.92

Splicing

Name	Calibrated prediction	Score	Prediction
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

Other links and lift over

dbSNP: rs753472891; hg19: chr17-78187645; COSMIC: COSV58338925; COSMIC: COSV58338925;