1-74204790-T-C

Variant summary

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

The NM_003838.5(FPGT):c.743T>C(p.Phe248Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,138 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/16 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: FPGT NM_003838.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.367

Genes affected

FPGT (HGNC:3825): (fucose-1-phosphate guanylyltransferase) L-fucose is a key sugar in glycoproteins and other complex carbohydrates since it may be involved in many of the functional roles of these macromolecules, such as in cell-cell recognition. The fucosyl donor for these fucosylated oligosaccharides is GDP-beta-L-fucose. There are two alternate pathways for the biosynthesis of GDP-fucose; the major pathway converts GDP-alpha-D-mannose to GDP-beta-L-fucose. The protein encoded by this gene participates in an alternate pathway that is present in certain mammalian tissues, such as liver and kidney, and appears to function as a salvage pathway to reutilize L-fucose arising from the turnover of glycoproteins and glycolipids. This pathway involves the phosphorylation of L-fucose to form beta-L-fucose-1-phosphate, and then condensation of the beta-L-fucose-1-phosphate with GTP by fucose-1-phosphate guanylyltransferase to form GDP-beta-L-fucose. Alternative splicing results in multiple transcript variants. Read-through transcription also exists between this gene and the neighboring downstream TNNI3 interacting kinase (TNNI3K) gene. [provided by RefSeq, Dec 2010]

FPGT-TNNI3K (HGNC:):

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=0.076532036).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FPGT	NM_003838.5	c.743T>C	p.Phe248Ser	missense_variant	4/4	ENST00000370898.9
FPGT-TNNI3K	NM_001112808.3	c.343+3380T>C		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FPGT	ENST00000370898.9	c.743T>C	p.Phe248Ser	missense_variant	4/4	1	NM_003838.5	P1
FPGT	ENST00000370894.9	c.344-418T>C		intron_variant		1
FPGT	ENST00000534056.5	c.409+334T>C		intron_variant		2
FPGT	ENST00000524915.5	n.448+334T>C		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152138 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152138 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74324

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

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: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 08, 2021

The c.743T>C (p.F248S) alteration is located in exon 4 (coding exon 4) of the FPGT gene. This alteration results from a T to C substitution at nucleotide position 743, causing the phenylalanine (F) at amino acid position 248 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.074
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.47
Cadd	Benign	6.8
Dann	Benign	0.67
Eigen	Benign	-0.93
Eigen_PC	Benign	-0.88
FATHMM_MKL	Benign	0.21	N
LIST_S2	Benign	0.51	T
M_CAP	Benign	0.0037	T
MetaRNN	Benign	0.077	T
MetaSVM	Benign	-0.96	T
MutationTaster	Benign	1.0	N;N;N;N;N;N
REVEL	Benign	0.046
Sift4G	Benign	0.46	T
Vest4		0.086
MVP		0.048
ClinPred		0.041	T
GERP RS		2.9
Varity_R		0.090
gMVP		0.35

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: rs1316054260; hg19: chr1-74670474;