rs118204441

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000512.5(GALNS):​c.280C>T​(p.Arg94Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,613,480 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. R94H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

GALNS
NM_000512.5 missense

Scores

14
4
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 2.43
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 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, 12 uncertain in NM_000512.5
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr16-88841935-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1048177.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.987
PP5
Variant 16-88841936-G-A is Pathogenic according to our data. Variant chr16-88841936-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 651205.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
GALNSNM_000512.5 linkuse as main transcriptc.280C>T p.Arg94Cys missense_variant 3/14 ENST00000268695.10

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
GALNSENST00000268695.10 linkuse as main transcriptc.280C>T p.Arg94Cys missense_variant 3/141 NM_000512.5 P1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152208
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.0000164
AC:
24
AN:
1461272
Hom.:
0
Cov.:
31
AF XY:
0.0000151
AC XY:
11
AN XY:
726890
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000207
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152208
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74366
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000594

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-IV-A Pathogenic:5
Pathogenic, criteria provided, single submitterclinical testingRevvity Omics, RevvitySep 16, 2021- -
Likely pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsJul 31, 2021- -
Likely pathogenic, criteria provided, single submitterclinical testingGenome-Nilou LabNov 07, 2021- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpApr 09, 2023For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Arg94 amino acid residue in GALNS. Other variant(s) that disrupt this residue have been observed in individuals with GALNS-related conditions (PMID: 7795586, 9298823, 10814710, 23876334, 29731656), which suggests that this may be a clinically significant amino acid residue. Experimental studies have shown that this missense change affects GALNS function (PMID: 7795586, 10814710). 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. ClinVar contains an entry for this variant (Variation ID: 651205). This missense change has been observed in individuals with mucopolysaccharidosis type IVa (PMID: 10814710, 23876334, 29731656). This variant is present in population databases (no rsID available, gnomAD 0.01%). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 94 of the GALNS protein (p.Arg94Cys). -
Likely pathogenic, criteria provided, single submitterresearchLaboratory of Diagnosis and Therapy of Lysosomal Disorders, University of PadovaFeb 01, 2021In vitro and vivo functional studies supportive of a damaging effect on the gene product (low to null enzymatic activity in homozygotes; low to null in vitro enzymatic activity; PS3_moderate); 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) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.53
BayesDel_addAF
Pathogenic
0.55
D
BayesDel_noAF
Pathogenic
0.55
CADD
Pathogenic
32
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.94
D;.
Eigen
Pathogenic
0.73
Eigen_PC
Uncertain
0.60
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Pathogenic
0.87
D
MetaRNN
Pathogenic
0.99
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.1
H;.
MutationTaster
Benign
1.0
D;D
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-7.5
D;D
REVEL
Pathogenic
0.98
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;.
Polyphen
1.0
D;.
Vest4
0.99
MutPred
0.94
Loss of MoRF binding (P = 0.0085);.;
MVP
1.0
MPC
0.59
ClinPred
1.0
D
GERP RS
4.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.96
gMVP
0.97

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs118204441; hg19: chr16-88908344; COSMIC: COSV51940717; COSMIC: COSV51940717; API