1-67009142-A-G

Position:

• chr1-67009142-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_015139.3(SLC35D1):​c.902T>C​(p.Met301Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000082 in 1,462,836 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M301I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000061 (0 hom.)
• Consequence: SLC35D1 NM_015139.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 8.39

Genes affected

SLC35D1 (HGNC:20800): (solute carrier family 35 member D1) Glycosylation of cellular glycoconjugates occurs in the endoplasmic reticulum (ER) and Golgi compartment, and requires transport of nucleotide sugars from the cytosol into the lumen of the ER and Golgi by specific transporters. The protein encoded by this gene resides in the ER, and transports both UDP-glucuronic acid (UDP-GlcA) and UDP-N-acetylgalactosamine (UDP-GalNAc) from the cytoplasm to the ER lumen. It may participate in glucuronidation and/or chondroitin sulfate biosynthesis. Mutations in this gene are associated with Schneckenbecken dysplasia.[provided by RefSeq, Sep 2009]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.878

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SLC35D1	NM_015139.3	c.902T>C	p.Met301Thr	missense_variant	11/12	ENST00000235345.6	NP_055954.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SLC35D1	ENST00000235345.6	c.902T>C	p.Met301Thr	missense_variant	11/12	1	NM_015139.3	ENSP00000235345.5

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152178 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000478

GnomAD4 exome AF: 0.00000610 AC: 8 AN: 1310658 Hom.: 0 Cov.: 20 AF XY: 0.00000759 AC XY: 5 AN XY: 658338

Gnomad4 AFR exome AF: 0.0000330

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: 0.00000204

Gnomad4 OTH exome AF: 0.0000913

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152178 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74344

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.000478

Bravo AF: 0.0000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 24, 2024

The c.902T>C (p.M301T) alteration is located in exon 11 (coding exon 11) of the SLC35D1 gene. This alteration results from a T to C substitution at nucleotide position 902, causing the methionine (M) at amino acid position 301 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Schneckenbecken dysplasia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 27, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with SLC35D1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces methionine with threonine at codon 301 of the SLC35D1 protein (p.Met301Thr). The methionine residue is highly conserved and there is a moderate physicochemical difference between methionine and threonine. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 12, 2021

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.48	T
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D
M_CAP	Benign	0.037	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Uncertain	0.035	D
MutationAssessor	Pathogenic	3.5	M
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-4.9	D
REVEL	Uncertain	0.59
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		0.99	D
Vest4		0.92
MutPred		0.61		Gain of catalytic residue at M301 (P = 0.0104);
MVP		0.90
MPC		0.75
ClinPred		1.0	D
GERP RS		6.0
Varity_R		0.90
gMVP		0.89

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: rs936897641; hg19: chr1-67474825;