8-19405914-G-T

Position:

• chr8-19405914-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001354483.2(CSGALNACT1):​c.1465C>A​(p.Gln489Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,876 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CSGALNACT1 NM_001354483.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.52

Genes affected

CSGALNACT1 (HGNC:24290): (chondroitin sulfate N-acetylgalactosaminyltransferase 1) This gene encodes an enzyme that transfers N-acetylglucosamine (GalNAc) to the core tetrasaccharide linker and to elongating chondroitin sulfate chains in proteoglycans. Knockout of the orthologous mouse gene indicates that the protein is necessary for normal cartilage development and aggrecan metabolism. Mutations in this gene are associated with multiple sclerosis progression, and with mild skeletal dysplasia and joint laxity. [provided by RefSeq, Aug 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.922

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CSGALNACT1	NM_001354483.2	c.1465C>A	p.Gln489Lys	missense_variant	9/9	ENST00000692225.2	NP_001341412.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CSGALNACT1	ENST00000692225.2	c.1465C>A	p.Gln489Lys	missense_variant	9/9		NM_001354483.2	ENSP00000509853.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461876 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727236

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 05, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. 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 not expected to disrupt CSGALNACT1 protein function. This variant has not been reported in the literature in individuals affected with CSGALNACT1-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces glutamine, which is neutral and polar, with lysine, which is basic and polar, at codon 489 of the CSGALNACT1 protein (p.Gln489Lys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.58
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.29	T;T;T
Eigen	Uncertain	0.65
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.87	.;.;D
M_CAP	Benign	0.035	D
MetaRNN	Pathogenic	0.92	D;D;D
MetaSVM	Benign	-0.77	T
MutationAssessor	Uncertain	2.4	M;M;M
PrimateAI	Uncertain	0.73	T
PROVEAN	Uncertain	-3.2	D;D;D
REVEL	Uncertain	0.53
Sift	Benign	0.058	T;T;T
Sift4G	Benign	0.090	T;T;T
Polyphen		0.48	P;P;P
Vest4		0.80
MutPred		0.86		Gain of ubiquitination at Q489 (P = 0.0219);Gain of ubiquitination at Q489 (P = 0.0219);Gain of ubiquitination at Q489 (P = 0.0219);
MVP		0.30
MPC		0.14
ClinPred		0.89	D
GERP RS		5.9
Varity_R		0.62
gMVP		0.88

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

Other links and lift over

dbSNP: rs1475561108; hg19: chr8-19263425;