16-88837686-C-A

Variant names:

• chr16-88837686-C-A
• rs775732598
• NM_000512.5:c.502G>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000512.5(GALNS):​c.502G>T​(p.Gly168*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GALNS NM_000512.5 stop_gained
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.60
• Publications: 1 publications found

Genes affected

GALNS (HGNC:4122): (galactosamine (N-acetyl)-6-sulfatase) This gene encodes N-acetylgalactosamine-6-sulfatase which is a lysosomal exohydrolase required for the degradation of the glycosaminoglycans, keratan sulfate, and chondroitin 6-sulfate. Sequence alterations including point, missense and nonsense mutations, as well as those that affect splicing, result in a deficiency of this enzyme. Deficiencies of this enzyme lead to Morquio A syndrome, a lysosomal storage disorder. [provided by RefSeq, Jul 2008]

GALNS Gene-Disease associations (from GenCC):

• mucopolysaccharidosis type 4A

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, ClinGen, Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-88837686-C-A is Pathogenic according to our data. Variant chr16-88837686-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1048280.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GALNS	NM_000512.5	c.502G>T	p.Gly168*	stop_gained	Exon 5 of 14	ENST00000268695.10	NP_000503.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GALNS	ENST00000268695.10	c.502G>T	p.Gly168*	stop_gained	Exon 5 of 14	1	NM_000512.5	ENSP00000268695.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mucopolysaccharidosis, MPS-IV-A Pathogenic:1

Feb 01, 2021

Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

Nonsense variant (PVS1_very strong); absent from gnomAD v2.1.1 (PM2_moderate) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	48
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Uncertain	0.93	D
PhyloP100		7.6
Vest4		0.87
GERP RS		5.2
Mutation Taster		=1/199	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs775732598; hg19: chr16-88904094; COSMIC: COSV51936737; COSMIC: COSV51936737;