1-111238768-T-C

Variant summary

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

The NM_004000.3(CHI3L2):c.754T>C(p.Trp252Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000547 in 1,461,684 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: 0.0000055 (0 hom.)
• Consequence: CHI3L2 NM_004000.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.41

Genes affected

CHI3L2 (HGNC:1933): (chitinase 3 like 2) The protein encoded by this gene is similar to bacterial chitinases but lacks chitinase activity. The encoded protein is secreted and is involved in cartilage biogenesis. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]

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, 0.966

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHI3L2	NM_004000.3	c.754T>C	p.Trp252Arg	missense_variant	8/11	ENST00000369748.9
CHI3L2	NM_001025197.1	c.724T>C	p.Trp242Arg	missense_variant	7/10
CHI3L2	NM_001025199.2	c.517T>C	p.Trp173Arg	missense_variant	7/10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHI3L2	ENST00000369748.9	c.754T>C	p.Trp252Arg	missense_variant	8/11	1	NM_004000.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461684 Hom.: 0 Cov.: 31 AF XY: 0.00000825 AC XY: 6 AN XY: 727142

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: 0.00000719

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 25, 2022

The c.754T>C (p.W252R) alteration is located in exon 8 (coding exon 8) of the CHI3L2 gene. This alteration results from a T to C substitution at nucleotide position 754, causing the tryptophan (W) at amino acid position 252 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.050
Cadd	Uncertain	25
Dann	Uncertain	0.99
DEOGEN2	Benign	0.17	T;.;T;.;.
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.81	D
M_CAP	Benign	0.019	T
MetaRNN	Pathogenic	0.97	D;D;D;D;D
MetaSVM	Benign	-0.98	T
MutationAssessor	Pathogenic	3.9	H;.;H;.;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Benign	0.48	T
PROVEAN	Pathogenic	-10	D;D;D;D;D
REVEL	Uncertain	0.30
Sift	Uncertain	0.0080	D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D
Polyphen		1.0	D;.;D;.;.
Vest4		0.89
MutPred		0.82		Gain of methylation at W252 (P = 0.0197);.;Gain of methylation at W252 (P = 0.0197);.;.;
MVP		0.30
MPC		0.13
ClinPred		1.0	D
GERP RS		3.4
Varity_R		0.98
gMVP		0.82

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-111781390;