16-17108872-C-G

Variant names:

• chr16-17108872-C-G
• rs769733883
• NM_022166.4:c.2703G>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.2703G>C​(p.Ala901Ala) 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 1,460,266 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. A901A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: XYLT1 NM_022166.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.916
• 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: Labcorp Genetics (formerly Invitae), G2P
• 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=-0.8).
• BP7: Synonymous conserved (PhyloP=-0.916 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.2703G>C	p.Ala901Ala	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.2703G>C	p.Ala901Ala	synonymous	Exon 12 of 12	ENSP00000261381.6	Q86Y38
	XYLT1	ENST00000933757.1		c.2700G>C	p.Ala900Ala	synonymous	Exon 12 of 12	ENSP00000603816.1
	ENSG00000261448	ENST00000567344.2	TSL:3	n.349-25594C>G		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250328 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: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460266 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726264

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.00 AC: 0 AN: 44686

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.00 AC: 0 AN: 86110

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52926

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5732

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111218

Other (OTH) AF: 0.00 AC: 0 AN: 60330

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	0.16
DANN	Benign	0.39
PhyloP100		-0.92

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: rs769733883; hg19: chr16-17202729;