12-63780019-C-G

Position:

• chr12-63780019-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_014254.3(RXYLT1):​c.59C>G​(p.Ser20Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000000686 in 1,458,154 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: RXYLT1 NM_014254.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.06

Genes affected

RXYLT1 (HGNC:13530): (ribitol xylosyltransferase 1) This gene encodes a type II transmembrane protein that is thought to have glycosyltransferase function. Mutations in this gene result in cobblestone lissencephaly. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, May 2013]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RXYLT1	NM_014254.3	c.59C>G	p.Ser20Cys	missense_variant	1/6	ENST00000261234.11	NP_055069.1
RXYLT1	XM_047428079.1	c.59C>G	p.Ser20Cys	missense_variant	1/5		XP_047284035.1
RXYLT1	NM_001278237.2	c.-1055C>G		5_prime_UTR_variant	1/6		NP_001265166.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RXYLT1	ENST00000261234.11	c.59C>G	p.Ser20Cys	missense_variant	1/6	1	NM_014254.3	ENSP00000261234	P1
	ENST00000509615.2	n.238+15462G>C		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1458154 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 725634

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 26, 2022

This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 20 of the RXYLT1 protein (p.Ser20Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with RXYLT1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
BayesDel_addAF	Uncertain	0.029	T
BayesDel_noAF	Benign	-0.20
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Benign	0.067	T
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Benign	0.73	D
LIST_S2	Uncertain	0.88	D
M_CAP	Uncertain	0.17	D
MetaRNN	Uncertain	0.65	D
MetaSVM	Benign	-0.88	T
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-1.6	N
REVEL	Benign	0.16
Sift	Uncertain	0.014	D
Sift4G	Uncertain	0.017	D
Polyphen		1.0	D
Vest4		0.61
MutPred		0.42		Gain of catalytic residue at L18 (P = 0);
MVP		0.14
MPC		2.3
ClinPred		0.98	D
GERP RS		3.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.44
gMVP		0.79

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: rs773907745; hg19: chr12-64173799; COSMIC: COSV54168394; COSMIC: COSV54168394;