chr15-101177420-T-C

Variant names:

• chr15-101177420-T-C
• rs960887600
• NM_014918.5:c.2377A>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_014918.5(CHSY1):​c.2377A>G​(p.Ser793Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,190 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: CHSY1 NM_014918.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.30
• Publications: 0 publications found

Genes affected

CHSY1 (HGNC:17198): (chondroitin sulfate synthase 1) This gene encodes a member of the chondroitin N-acetylgalactosaminyltransferase family. These enzymes possess dual glucuronyltransferase and galactosaminyltransferase activity and play critical roles in the biosynthesis of chondroitin sulfate, a glycosaminoglycan involved in many biological processes including cell proliferation and morphogenesis. Decreased expression of this gene may play a role in colorectal cancer, and mutations in this gene are a cause of temtamy preaxial brachydactyly syndrome. [provided by RefSeq, Dec 2011]

CHSY1 Gene-Disease associations (from GenCC):

• temtamy preaxial brachydactyly syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.057504).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHSY1	NM_014918.5	c.2377A>G	p.Ser793Gly	missense_variant	Exon 3 of 3	ENST00000254190.4	NP_055733.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHSY1	ENST00000254190.4	c.2377A>G	p.Ser793Gly	missense_variant	Exon 3 of 3	1	NM_014918.5	ENSP00000254190.3
CHSY1	ENST00000543813.2	n.*1692A>G		non_coding_transcript_exon_variant	Exon 3 of 3	2		ENSP00000496160.1
CHSY1	ENST00000543813.2	n.*1692A>G		3_prime_UTR_variant	Exon 3 of 3	2		ENSP00000496160.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000400 AC: 1 AN: 249998 AF XY: 0.00000739

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: 0.00000886

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461190 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 726820

African (AFR) AF: 0.00 AC: 0 AN: 33448

American (AMR) AF: 0.00 AC: 0 AN: 44576

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26116

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86016

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111804

Other (OTH) AF: 0.00 AC: 0 AN: 60358

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000468 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Temtamy preaxial brachydactyly syndrome Uncertain:1

Oct 13, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces serine, which is neutral and polar, with glycine, which is neutral and non-polar, at codon 793 of the CHSY1 protein (p.Ser793Gly). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CHSY1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1506765). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The glycine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.054
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.70
CADD	Benign	14
DANN	Benign	0.75
DEOGEN2	Benign	0.0072	T
Eigen	Benign	-0.67
Eigen_PC	Benign	-0.51
FATHMM_MKL	Benign	0.75	D
LIST_S2	Benign	0.53	T
M_CAP	Benign	0.0045	T
MetaRNN	Benign	0.058	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.55	N
PhyloP100		1.3
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-0.080	N
REVEL	Benign	0.042
Sift	Benign	0.22	T
Sift4G	Benign	0.26	T
Polyphen		0.0	B
Vest4		0.056
MutPred		0.099		Loss of glycosylation at S793 (P = 0.0311);
MVP		0.28
MPC		0.29
ClinPred		0.077	T
GERP RS		1.8
Varity_R		0.059
gMVP		0.33
Mutation Taster		=85/15	polymorphism

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: rs960887600; hg19: chr15-101717625;