16-88837686-C-T

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

11
5
3

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

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
GALNSNM_000512.5 linkc.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
GALNSENST00000268695.10 linkc.502G>A p.Gly168Arg missense_variant Exon 5 of 14 1 NM_000512.5 ENSP00000268695.5 P34059

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152148
Hom.:
0
Cov.:
32
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:
4
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:
7
AN:
1461800
Hom.:
0
Cov.:
32
AF XY:
0.00000413
AC XY:
3
AN XY:
727206
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53354
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111996
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.432
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
2
AN:
152148
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74328
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41428
American (AMR)
AF:
0.0000655
AC:
1
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000824
AC:
1

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
D
BayesDel_noAF
Pathogenic
0.41
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.82
D;.
Eigen
Pathogenic
0.77
Eigen_PC
Pathogenic
0.73
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Uncertain
0.97
D;D
M_CAP
Pathogenic
0.82
D
MetaRNN
Pathogenic
0.97
D;D
MetaSVM
Pathogenic
0.88
D
MutationAssessor
Benign
1.4
L;.
PhyloP100
7.6
PrimateAI
Uncertain
0.77
T
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
D
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)

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

Other links and lift over

dbSNP: rs775732598; hg19: chr16-88904094; API