8-19405784-GTT-GTTT

Variant names:

• chr8-19405784-G-GT
• rs778908076
• NM_001354483.2:c.1594dupA

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_001354483.2(CSGALNACT1):​c.1594dupA​(p.Thr532AsnfsTer31) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,614,006 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000015 (0 hom.)
• Consequence: CSGALNACT1 NM_001354483.2 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.981
• Publications: 0 publications found

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]

CSGALNACT1 Gene-Disease associations (from GenCC):

• skeletal dysplasia, mild, with joint laxity and advanced bone age

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.00313 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001354483.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CSGALNACT1	NM_001354483.2	MANE Select	c.1594dupA	p.Thr532AsnfsTer31	frameshift	Exon 9 of 9	NP_001341412.1	Q8TDX6-1
	CSGALNACT1	NM_001130518.2		c.1594dupA	p.Thr532AsnfsTer31	frameshift	Exon 10 of 10	NP_001123990.1	Q8TDX6-1
	CSGALNACT1	NM_001354475.2		c.1594dupA	p.Thr532AsnfsTer31	frameshift	Exon 10 of 10	NP_001341404.1	Q8TDX6-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CSGALNACT1	ENST00000692225.2	MANE Select	c.1594dupA	p.Thr532AsnfsTer31	frameshift	Exon 9 of 9	ENSP00000509853.1	Q8TDX6-1
	CSGALNACT1	ENST00000332246.10	TSL:1	c.1594dupA	p.Thr532AsnfsTer31	frameshift	Exon 10 of 10	ENSP00000330805.6	Q8TDX6-1
	CSGALNACT1	ENST00000454498.6	TSL:1	c.1594dupA	p.Thr532AsnfsTer31	frameshift	Exon 10 of 10	ENSP00000411816.2	Q8TDX6-1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152154 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

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

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251358 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000150 AC: 22 AN: 1461852 Hom.: 0 Cov.: 31 AF XY: 0.0000124 AC XY: 9 AN XY: 727234

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.0000756 AC: 3 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53384

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000153 AC: 17 AN: 1112010

Other (OTH) AF: 0.0000331 AC: 2 AN: 60394

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152154 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74334

African (AFR) AF: 0.0000241 AC: 1 AN: 41424

American (AMR) AF: 0.00 AC: 0 AN: 15276

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68032

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.98
Mutation Taster		=17/183	disease causing

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

Other links and lift over

dbSNP: rs778908076; hg19: chr8-19263295; COSMIC: COSV59973150;