rs371429653

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PP3PP5

The NM_000512.5(GALNS):​c.245C>T​(p.Ser82Leu) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000993 in 1,611,214 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. 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. S82P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

GALNS
NM_000512.5 missense, splice_region

Scores

7
4
2
Splicing: ADA: 0.9965
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:7U:1

Conservation

PhyloP100: 9.78

Publications

6 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: Likely_pathogenic. The variant received 6 ACMG points.

PM1
In a hotspot region, there are 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in NM_000512.5
PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
PP5
Variant 16-88841971-G-A is Pathogenic according to our data. Variant chr16-88841971-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 93175.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GALNSNM_000512.5 linkc.245C>T p.Ser82Leu missense_variant, splice_region_variant Exon 3 of 14 ENST00000268695.10 NP_000503.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GALNSENST00000268695.10 linkc.245C>T p.Ser82Leu missense_variant, splice_region_variant Exon 3 of 14 1 NM_000512.5 ENSP00000268695.5

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152206
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000482
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000124
AC:
3
AN:
242556
AF XY:
0.00000760
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000274
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000891
AC:
13
AN:
1459008
Hom.:
0
Cov.:
31
AF XY:
0.0000138
AC XY:
10
AN XY:
725560
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33438
American (AMR)
AF:
0.00
AC:
0
AN:
44338
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26084
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39632
South Asian (SAS)
AF:
0.0000233
AC:
2
AN:
85656
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53136
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00000900
AC:
10
AN:
1110700
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60260
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000197
AC:
3
AN:
152206
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74346
show subpopulations
African (AFR)
AF:
0.0000482
AC:
2
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
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:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.558
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000475
Hom.:
0
Bravo
AF:
0.0000189
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00000826
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:7Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-IV-A Pathogenic:6
Jan 02, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 82 of the GALNS protein (p.Ser82Leu). This variant is present in population databases (rs371429653, gnomAD 0.003%). This missense change has been observed in individual(s) with mucopolysaccharidosis type IVA (PMID: 20574428, 23876334). ClinVar contains an entry for this variant (Variation ID: 93175). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. For these reasons, this variant has been classified as Pathogenic. -

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

In vivo functional studies supportive of a damaging effect on the gene product (low to null enzymatic activity in homozygotes; PS3_supporting); the prevalence of the variant in affected individuals is significantly increased compared with the prevalence in controls (PS4_strong); absent from gnomAD v2.1.1 (PM2_moderate); multiple lines of computational evidence support a deleterious effect on the gene (PP3_supporting) -

Nov 07, 2021
Genome-Nilou Lab
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 19, 2021
Centre for Inherited Metabolic Diseases, Karolinska University Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Neuberg Centre For Genomic Medicine, NCGM
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The missense c.245C>T(p.Ser82Leu) variant, lying in splice region of GALNS gene has been reported previously in compound heterozygous and homozygous states in multiple individuals affected with Mucopolysaccharidosis IVA (Dũng VC, et. al., 2013; Zanetti et. al., 2021; Stranneheim et. al., 2021). This p.Ser82Leu variant is present with an allele frequency of 0.001% in gnomAD Exomes. This variant has been reported to the ClinVar database as Uncertain Significance / Pathogenic / Likely pathogenic. Multiple lines of computational evidence (Polyphen - Probably Damaging , SIFT - Damaging and MutationTaster - Disease causing) predict damaging effect on protein structure and function for this variant. The reference amino acid at this position on GALNS gene is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. The amino acid Ser at position 82 is changed to a Leu changing protein sequence and it might alter its composition and physico-chemical properties. However, functional studies are required to prove the pathogenicity of this variant conclusively. For these reasons, this variant has been classified as Likely Pathogenic. -

Mar 14, 2024
Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Morquio syndrome Pathogenic:1
Jun 03, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: GALNS c.245C>T (p.Ser82Leu) results in a non-conservative amino acid change located in the Sulfatase, N-terminal domain (IPR000917) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. 4/4 computational tools predict no significant impact on normal splicing, however, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.2e-05 in 242556 control chromosomes (gnomAD). c.245C>T has been reported in the literature in compound heterozygous and homozygous individuals affected with Mucopolysaccharidosis Type IVA (Morquio Syndrome A, e.g. Wang_2010, Dung_2013, Bidchol_2014). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five ClinVar submitters have assessed the variant since 2014: one classified the variant as VUS, two as likely pathogenic, and two as pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided Uncertain:1
Jan 05, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.87
BayesDel_addAF
Uncertain
0.093
D
BayesDel_noAF
Pathogenic
0.55
CADD
Pathogenic
34
DANN
Uncertain
1.0
Eigen
Pathogenic
0.89
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.26
T
M_CAP
Pathogenic
0.90
D
MetaRNN
Pathogenic
0.92
D
PhyloP100
9.8
PROVEAN
Uncertain
-2.4
N
Sift
Uncertain
0.0020
D
MVP
0.97
ClinPred
1.0
D
GERP RS
5.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.97
Mutation Taster
=4/96
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.93
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

Other links and lift over

dbSNP: rs371429653; hg19: chr16-88908379; API