chr16-88837686-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong

The NM_000512.5(GALNS):c.502G>A(p.Gly168Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,948 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. G168V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

GALNS
NM_000512.5 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 7.60

Publications

8 publications found

Variant links:

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

GALNS links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PM1

In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000512.5

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.974

PP5

Variant 16-88837686-C-T is Pathogenic according to our data. Variant chr16-88837686-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 528319.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GALNS	NM_000512.5 link	c.502G>A	p.Gly168Arg	missense_variant	Exon 5 of 14	ENST00000268695.10	NP_000503.1	P34059Q96I49

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GALNS	ENST00000268695.10 link	c.502G>A	p.Gly168Arg	missense_variant	Exon 5 of 14	1	NM_000512.5	ENSP00000268695.5		P34059

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152148

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

251428

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS 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:

0.00000479

AC:

AN:

1461800

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727206

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000894

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53354

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5758

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111996

Other (OTH)

AF:

0.0000166

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.432

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74328

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41428

American (AMR)

AF:

0.0000655

AC:

AN:

15270

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-IV-A

Pathogenic:5

Apr 30, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

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:research

The prevalence of the variant in affected individuals is significantly increased compared with the prevalence in controls (PS4_strong); very low frequency in gnomAD v2.1.1 (PM2_moderate); multiple lines of computational evidence support a deleterious effect on the gene (PP3_supporting) -

Jun 14, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 168 of the GALNS protein (p.Gly168Arg). This variant is present in population databases (rs775732598, gnomAD 0.01%). This missense change has been observed in individual(s) with mucopolysaccharidosis type IVA (PMID: 9298823, 29275451, 30927141; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 528319). 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 GALNS protein function with a positive predictive value of 95%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Nov 07, 2021

Genome-Nilou Lab

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 09, 2021

Revvity Omics, Revvity

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Morquio syndrome

Pathogenic:1

Apr 07, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: GALNS c.502G>A (p.Gly168Arg) results in a non-conservative amino acid change in 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 1.6e-05 in 251428 control chromosomes. c.502G>A has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type IVA (Morquio Syndrome A). These data indicate that the variant is very likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 29275451, 9298823). ClinVar contains an entry for this variant (Variation ID: 528319). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided

Pathogenic:1

Feb 16, 2025

Laboratory of Genetics, Children's Clinical University Hospital Latvia

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.73

BayesDel_addAF

Pathogenic

0.29

BayesDel_noAF

Pathogenic

0.41

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.82

D;.

Eigen

Pathogenic

0.77

Eigen_PC

Pathogenic

0.73

FATHMM_MKL

Uncertain

0.92

LIST_S2

Uncertain

0.97

D;D

M_CAP

Pathogenic

0.82

MetaRNN

Pathogenic

0.97

D;D

MetaSVM

Pathogenic

0.88

MutationAssessor

Benign

1.4

L;.

PhyloP100

7.6

PrimateAI

Uncertain

0.77

PROVEAN

Uncertain

-3.8

D;D

REVEL

Pathogenic

0.89

Sift

Benign

0.16

T;T

Sift4G

Uncertain

0.053

T;.

Polyphen

1.0

D;.

Vest4

0.95

MutPred

0.88

Loss of ubiquitination at K173 (P = 0.0461);.;

MVP

1.0

MPC

0.55

ClinPred

0.93

GERP RS

5.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.92

gMVP

0.97

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over