1-23845738-T-C

Position:

• chr1-23845738-T-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000147.5(FUCA1):​c.1378A>G​(p.Ile460Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FUCA1 NM_000147.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -2.15

Genes affected

FUCA1 (HGNC:4006): (alpha-L-fucosidase 1) The protein encoded by this gene is a lysosomal enzyme involved in the degradation of fucose-containing glycoproteins and glycolipids. Mutations in this gene are associated with fucosidosis (FUCA1D), which is an autosomal recessive lysosomal storage disease. A pseudogene of this locus is present on chr 2.[provided by RefSeq, Oct 2009]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.04221067).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FUCA1	NM_000147.5	c.1378A>G	p.Ile460Val	missense_variant	8/8	ENST00000374479.4	NP_000138.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FUCA1	ENST00000374479.4	c.1378A>G	p.Ile460Val	missense_variant	8/8	1	NM_000147.5	ENSP00000363603	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251424 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135880

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461882 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

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

Dec 18, 2023

The c.1378A>G (p.I460V) alteration is located in exon 8 (coding exon 8) of the FUCA1 gene. This alteration results from a A to G substitution at nucleotide position 1378, causing the isoleucine (I) at amino acid position 460 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Fucosidosis Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 09, 2021

This variant has not been reported in the literature in individuals affected with FUCA1-related conditions. 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 output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant is present in population databases (rs774128532, gnomAD 0.006%). This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 460 of the FUCA1 protein (p.Ile460Val). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	-0.44	T
BayesDel_noAF	Benign	-0.70
CADD	Benign	0.050
DANN	Benign	0.69
DEOGEN2	Benign	0.15	T
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.7
FATHMM_MKL	Benign	0.013	N
LIST_S2	Benign	0.66	T
M_CAP	Benign	0.0035	T
MetaRNN	Benign	0.042	T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	0.48	N
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-0.81	N
REVEL	Benign	0.10
Sift	Benign	0.11	T
Sift4G	Benign	0.14	T
Polyphen		0.0	B
Vest4		0.038
MutPred		0.49		Gain of catalytic residue at I460 (P = 0.0363);
MVP		0.19
MPC		0.27
ClinPred		0.032	T
GERP RS		-11
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.059
gMVP		0.57

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs774128532; hg19: chr1-24172228;