rs775112689

chr17-80214705-G-Achr17-80214705-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP5

The NM_000199.5(SGSH):c.416C>T(p.Thr139Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,612,986 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T139S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000096 (0 hom.)
• Consequence: SGSH NM_000199.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4 U:3
• Conservation: PhyloP100: 9.81

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-80214705-G-A is Pathogenic according to our data. Variant chr17-80214705-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 551670.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=3}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SGSH	NM_000199.5	c.416C>T	p.Thr139Met	missense_variant	4/8	ENST00000326317.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SGSH	ENST00000326317.11	c.416C>T	p.Thr139Met	missense_variant	4/8	1	NM_000199.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152206 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.000288

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000798 AC: 2 AN: 250682 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135794

Gnomad AFR exome AF: 0.0000618

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: 0.00000884

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000958 AC: 14 AN: 1460780 Hom.: 0 Cov.: 33 AF XY: 0.00000688 AC XY: 5 AN XY: 726694

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000190

Gnomad4 NFE exome AF: 0.00000899

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152206 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74352

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.000288

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000478 Hom.: 0

Bravo AF: 0.0000189

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4 Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Mucopolysaccharidosis, MPS-III-A Pathogenic:3 Uncertain:3

Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	-	The missense variant p.T139M in SGSH (NM_000199.5) has been submitted previously to ClinVar with conflicting interpretations of pathogenicity (Likely Pathogenic/ Uncertain Significance). No details for independent assesment are available for the Likely Pathogenic classification. It has not been reported previously in affected individuals to the best of our knowledge. The p.T139M variant is observed in 1/16,194 (0.0062%) alleles from individuals of African background in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes.The p.T139M missense variant is predicted to be damaging by both SIFT and PolyPhen2. The threonine residue at codon 139 of SGSH is conserved in all mammalian species. The nucleotide c.416 in SGSH is predicted conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Uncertain Significance. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 20, 2023	- -
Pathogenic, no assertion criteria provided	research	Section for Clinical Neurogenetics, University of Tübingen	Aug 01, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Sep 02, 2022	This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 139 of the SGSH protein (p.Thr139Met). This variant is present in population databases (rs775112689, gnomAD 0.004%). This missense change has been observed in individual(s) with Sanfilippo syndrome (PMID: 9285796, 24576347). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 551670). 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: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Nov 12, 2021	NM_000199.3(SGSH):c.416C>T(T139M) is a missense variant classified as a variant of uncertain significance in the context of mucopolysaccharidosis type IIIA. T139M has been observed in cases with relevant disease (PMID: 9285796; 24576347). Functional assessments of this variant are not available in the literature. T139M has been observed in population frequency databases (gnomAD: AFR 0.01%). In summary, there is insufficient evidence to classify NM_000199.3(SGSH):c.416C>T(T139M) as pathogenic or benign. Please note: this variant was assessed in the context of healthy population screening. -

Intellectual disability Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Institute of Human Genetics, University of Leipzig Medical Center

Feb 25, 2021

The variant chr17-78188504-G-A, SGSH(NM_000199.5):c.416C>T,p.(Thr139Met) was identified in an individual with NDD. Inheritance was not applicable (heterozygous). The variant was reviewed according to current ACMG recommendations and classified as Likely Pathogenic (criteria: PM2_Supporting, PM3_Strong, PP3_Supporting, PP4_Supporting). This variant was identified in a compound heterozygous state with the variantNM_000199.5(SGSH):c.267C>A (p.Tyr89Ter) ( Variation ID: 983123). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.44
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Pathogenic	0.51
Cadd	Pathogenic	26
Dann	Uncertain	1.0
Eigen	Pathogenic	0.75
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.43	T
M_CAP	Pathogenic	0.60	D
MetaRNN	Uncertain	0.66	D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D;D;D
Sift4G	Uncertain	0.028	D
Vest4		0.43
MVP		0.85
ClinPred		0.98	D
GERP RS		4.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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: rs775112689; hg19: chr17-78188504;