rs727503946

Variant names:

• chr16-88841935-C-A
• rs727503946
• NM_000512.5:c.281G>T

Your query was ambiguous. Multiple possible variants found:

• chr16-88841935-C-A
• chr16-88841935-C-T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. R94C) 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
• Publications: 0 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 17 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 Pathogenic/Likely_pathogenic. ClinVar VariationId 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 Pathogenic/Likely_pathogenic. ClinVar VariationId is 1048177.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000512.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GALNS	NM_000512.5	MANE Select	c.281G>T	p.Arg94Leu	missense	Exon 3 of 14	NP_000503.1
	GALNS	NM_001323544.2		c.299G>T	p.Arg100Leu	missense	Exon 4 of 15	NP_001310473.1
	GALNS	NM_001323543.2		c.-275G>T		5_prime_UTR	Exon 2 of 13	NP_001310472.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GALNS	ENST00000268695.10	TSL:1 MANE Select	c.281G>T	p.Arg94Leu	missense	Exon 3 of 14	ENSP00000268695.5
	GALNS	ENST00000562593.5	TSL:1	n.3690G>T		non_coding_transcript_exon	Exon 1 of 12
	GALNS	ENST00000565364.1	TSL:1	n.416G>T		non_coding_transcript_exon	Exon 4 of 6

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

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_moderate); absent from gnomAD v2.1.1 (PM2_moderate); multiple lines of computational evidence support a deleterious effect on the gene (PP3_supporting)

May 04, 2022

Mendelics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Morquio syndrome Pathogenic:1

Jul 26, 2023

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.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 v4.9

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
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.0	M
PhyloP100		7.7
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-6.5	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	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
Mutation Taster		=12/88	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
Splicevardb		2.0
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

Other links and lift over

dbSNP: rs727503946; hg19: chr16-88908343;