1-23845807-C-G

Position:

• chr1-23845807-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000147.5(FUCA1):​c.1309G>C​(p.Asp437His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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)
• Consequence: FUCA1 NM_000147.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.03

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.087538004).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FUCA1	NM_000147.5	c.1309G>C	p.Asp437His	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.1309G>C	p.Asp437His	missense_variant	8/8	1	NM_000147.5	ENSP00000363603	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Fucosidosis Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 03, 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 tolerated, 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 FUCA1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces aspartic acid with histidine at codon 437 of the FUCA1 protein (p.Asp437His). The aspartic acid residue is weakly conserved and there is a moderate physicochemical difference between aspartic acid and histidine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.092
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.55
CADD	Benign	0.39
DANN	Benign	0.67
DEOGEN2	Benign	0.36	T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.033	N
LIST_S2	Benign	0.29	T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.088	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.83	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.21	T
PROVEAN	Benign	-1.9	N
REVEL	Benign	0.11
Sift	Benign	0.055	T
Sift4G	Benign	0.078	T
Polyphen		0.0010	B
Vest4		0.20
MutPred		0.27		Loss of ubiquitination at K438 (P = 0.0356);
MVP		0.17
MPC		0.38
ClinPred		0.070	T
GERP RS		-3.0
Varity_R		0.12
gMVP		0.51

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1639125891; hg19: chr1-24172297;