12-64714129-C-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_002076.4(GNS):c.*2612G>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000139 in 150,754 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00014 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: GNS NM_002076.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.56

Genes affected

GNS (HGNC:4422): (glucosamine (N-acetyl)-6-sulfatase) The product of this gene is a lysosomal enzyme found in all cells. It is involved in the catabolism of heparin, heparan sulphate, and keratan sulphate. Deficiency of this enzyme results in the accumulation of undegraded substrate and the lysosomal storage disorder mucopolysaccharidosis type IIID (Sanfilippo D syndrome). Mucopolysaccharidosis type IIID is the least common of the four subtypes of Sanfilippo syndrome. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BS1: Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000139 (21/150754) while in subpopulation SAS AF= 0.00084 (4/4762). AF 95% confidence interval is 0.000287. There are 0 homozygotes in gnomad4. There are 13 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GNS	NM_002076.4	c.*2612G>T		3_prime_UTR_variant	14/14	ENST00000258145.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GNS	ENST00000258145.8	c.*2612G>T		3_prime_UTR_variant	14/14	1	NM_002076.4	P1
GNS	ENST00000418919.6	c.*2612G>T		3_prime_UTR_variant	13/13	1

Frequencies

GnomAD3 genomes AF: 0.000139 AC: 21 AN: 150640 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000132

Gnomad ASJ AF: 0.00202

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000839

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000104

Gnomad OTH AF: 0.000483

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 2 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 2

Gnomad4 NFE exome AF: 0.00

GnomAD4 genome AF: 0.000139 AC: 21 AN: 150754 Hom.: 0 Cov.: 32 AF XY: 0.000177 AC XY: 13 AN XY: 73586

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000132

Gnomad4 ASJ AF: 0.00202

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000840

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000104

Gnomad4 OTH AF: 0.000478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mucopolysaccharidosis, MPS-III-D Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
Cadd	Benign	3.3
Dann	Benign	0.80

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs533328232; hg19: chr12-65107909;