rs727503946

chr16-88841935-C-Achr16-88841935-C-T

Variant summary

Our verdict is Pathogenic. Variant got 20 ACMG points: 20P and 0B. PS1_Moderate PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000512.5(GALNS):c.281G>T(p.Arg94Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin UniProt. 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: not found (cov: 33)
• Consequence: GALNS NM_000512.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.74

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]

ACMG classification

Verdict is Pathogenic. Variant got 20 ACMG points.

• PS1: Transcript NM_000512.5 (GALNS) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt
• PM1: In a hotspot region, there are 4 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 chr16-88841936-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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 16-88841935-C-A is Pathogenic according to our data. 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GALNS	NM_000512.5	c.281G>T	p.Arg94Leu	missense_variant	3/14	ENST00000268695.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GALNS	ENST00000268695.10	c.281G>T	p.Arg94Leu	missense_variant	3/14	1	NM_000512.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Mucopolysaccharidosis, MPS-IV-A Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 04, 2022	- -
Likely pathogenic, criteria provided, single submitter	research	Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova	Feb 01, 2021	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_moderate); absent from gnomAD v2.1.1 (PM2_moderate); multiple lines of computational evidence support a deleterious effect on the gene (PP3_supporting) -

Morquio syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

Jul 26, 2023

Variant summary: GALNS c.281G>T (p.Arg94Leu) 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. The variant was absent in 247782 control chromosomes (gnomAD). c.281G>T has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type IVA (Morquio Syndrome A) (examples: Tomatsu_2005, Morrone_2014, Bochernistan_Meta Gene_2018 ). 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: 24726177, 16287098). Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
Cadd	Pathogenic	30
Dann	Benign	0.97
DEOGEN2	Pathogenic	0.91	D;.
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.0	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-6.5	D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;.
Polyphen		1.0	D;.
Vest4		0.99
MutPred		0.98		Loss of MoRF binding (P = 0.0123);.;
MVP		1.0
MPC		0.56
ClinPred		1.0	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.98

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr16-88908343;