chr16-88824838-T-C

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.1171A>G​(p.Met391Val) variant causes a missense change. The variant allele was found at a frequency of 0.000013 in 1,613,224 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 Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

GALNS
NM_000512.5 missense

Scores

5
6
8

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 5.74

Publications

15 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

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ACMG classification

Classification was made for transcript

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

PM1
In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 9 uncertain in NM_000512.5
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.98
PP5
Variant 16-88824838-T-C is Pathogenic according to our data. Variant chr16-88824838-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 93162.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.1171A>G p.Met391Val missense_variant Exon 11 of 14 ENST00000268695.10 NP_000503.1 P34059Q96I49

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GALNSENST00000268695.10 linkc.1171A>G p.Met391Val missense_variant Exon 11 of 14 1 NM_000512.5 ENSP00000268695.5 P34059

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152164
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000801
AC:
2
AN:
249748
AF XY:
0.00
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:
0.00000889
Gnomad OTH exome
AF:
0.000164
GnomAD4 exome
AF:
0.0000123
AC:
18
AN:
1461060
Hom.:
0
Cov.:
32
AF XY:
0.0000151
AC XY:
11
AN XY:
726808
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52664
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000153
AC:
17
AN:
1111958
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60382
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.447
Heterozygous variant carriers
0
2
4
5
7
9
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:
152164
Hom.:
0
Cov.:
33
AF XY:
0.0000404
AC XY:
3
AN XY:
74306
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41442
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
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:
0.0000280
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-IV-A Pathogenic:4
Nov 07, 2021
Genome-Nilou Lab
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 15, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 14, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 391 of the GALNS protein (p.Met391Val). This variant is present in population databases (rs398123429, gnomAD 0.002%). This missense change has been observed in individual(s) with mucopolysaccharidosis IVA (PMID: 7668283, 9375852, 25137622). ClinVar contains an entry for this variant (Variation ID: 93162). 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%. Experimental studies have shown that this missense change affects GALNS function (PMID: 9375852). 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:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

In vitro and in vivo functional studies supportive of a damaging effect on the gene product (low to null in vitro enzymatic activity; low to null enzymatic activity in homozygotes; PS3_strong); 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) -

Morquio syndrome Pathogenic:1
Jun 15, 2020
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.1171A>G (p.Met391Val) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 249748 control chromosomes. c.1171A>G has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type IVA (Morquio Syndrome A) (example, Tomatsu_1995, Morrone_2014, Dung_2014). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity in a transient expression system (Tomatsu_1995). No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 although one submitter has classified the variant as pathogenic before 2014. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1
Jun 13, 2013
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.40
BayesDel_addAF
Pathogenic
0.41
D
BayesDel_noAF
Pathogenic
0.37
CADD
Benign
21
DANN
Benign
0.87
DEOGEN2
Uncertain
0.66
D
Eigen
Benign
-0.056
Eigen_PC
Benign
0.031
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.85
T
M_CAP
Uncertain
0.21
D
MetaRNN
Pathogenic
0.98
D
MetaSVM
Uncertain
-0.18
T
MutationAssessor
Pathogenic
3.2
M
PhyloP100
5.7
PrimateAI
Uncertain
0.55
T
PROVEAN
Benign
-2.0
N
REVEL
Pathogenic
0.71
Sift
Benign
0.10
T
Sift4G
Benign
0.28
T
Polyphen
0.56
P
Vest4
0.96
MutPred
0.88
Gain of sheet (P = 0.0344);
MVP
0.93
MPC
0.22
ClinPred
0.36
T
GERP RS
4.7
Varity_R
0.37
gMVP
0.89
Mutation Taster
=9/91
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: rs398123429; hg19: chr16-88891246; API