16-17108881-C-G

Variant names:

• chr16-17108881-C-G
• rs141353269
• NM_022166.4:c.2694G>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_022166.4(XYLT1):​c.2694G>C​(p.Thr898Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,480 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. T898T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: XYLT1 NM_022166.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -4.96
• Publications: 0 publications found

Genes affected

XYLT1 (HGNC:15516): (xylosyltransferase 1) This locus encodes a xylosyltransferase enzyme. The encoded protein catalyzes transfer of UDP-xylose to serine residues of an acceptor protein substrate. This transfer reaction is necessary for biosynthesis of glycosaminoglycan chains. Mutations in this gene have been associated with increased severity of pseudoxanthoma elasticum.[provided by RefSeq, Nov 2009]

XYLT1 Gene-Disease associations (from GenCC):

• Desbuquois dysplasia 2

  Inheritance: AR Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• Desbuquois dysplasia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• XYLT1-congenital disorder of glycosylation

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000261448 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.82).
• BP7: Synonymous conserved (PhyloP=-4.96 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_022166.4. 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
	XYLT1	NM_022166.4	MANE Select	c.2694G>C	p.Thr898Thr	synonymous	Exon 12 of 12	NP_071449.1	Q86Y38

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	XYLT1	ENST00000261381.7	TSL:1 MANE Select	c.2694G>C	p.Thr898Thr	synonymous	Exon 12 of 12	ENSP00000261381.6	Q86Y38
	XYLT1	ENST00000933757.1		c.2691G>C	p.Thr897Thr	synonymous	Exon 12 of 12	ENSP00000603816.1
	ENSG00000261448	ENST00000567344.2	TSL:3	n.349-25585C>G		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459480 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 725720

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

American (AMR) AF: 0.00 AC: 0 AN: 44654

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39648

South Asian (SAS) AF: 0.00 AC: 0 AN: 85998

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53046

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5734

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1110548

Other (OTH) AF: 0.00 AC: 0 AN: 60290

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
CADD	Benign	0.045
DANN	Benign	0.42
PhyloP100		-5.0

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: rs141353269; hg19: chr16-17202738;