15-101177638-T-A

Position:

• chr15-101177638-T-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_014918.5(CHSY1):​c.2159A>T​(p.Asp720Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,890 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: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CHSY1 NM_014918.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 7.82

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.947

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHSY1	NM_014918.5	c.2159A>T	p.Asp720Val	missense_variant	3/3	ENST00000254190.4	NP_055733.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHSY1	ENST00000254190.4	c.2159A>T	p.Asp720Val	missense_variant	3/3	1	NM_014918.5	ENSP00000254190.3
CHSY1	ENST00000543813.2	n.*1474A>T		non_coding_transcript_exon_variant	3/3	2		ENSP00000496160.1
CHSY1	ENST00000543813.2	n.*1474A>T		3_prime_UTR_variant	3/3	2		ENSP00000496160.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461890 Hom.: 0 Cov.: 67 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Temtamy preaxial brachydactyly syndrome Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Department of Laboratory Medicine, Örebro University Hospital

Jun 07, 2024

Thie variant c.2159A>T in CHSY1-gene causes an amino acid change from Asp to Val at position 720 in exon 3. The variant is not previously reported in the literature and is found at very low frequency in GnomAD database. Our in-house data shows that the variant was found in homozygous state in two unrelated families and co-segregates with disorder in affected family members. Patients' phenotype was highly specific for Temtamy preaxial brachydactyly syndrome. All used in-silico tools unanimously predict variant as pathogenic. Thus the variant is classified as Likely pathogenic. Criteria applied: PM2, PP3_mod, PP1, PP4. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Jul 01, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	30
DANN	Uncertain	0.99
DEOGEN2	Benign	0.33	T
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Uncertain	0.38	D
MutationAssessor	Pathogenic	3.4	M
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-8.7	D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.82		Gain of helix (P = 0.0164);
MVP		0.92
MPC		1.3
ClinPred		1.0	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.92
gMVP		0.97

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: rs2038210214; hg19: chr15-101717843;