Genetic Variant BFSP1:p.Thr648Ile (chr20-17494129-G-A) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

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

The NM_001195.5(BFSP1):c.1943C>T(p.Thr648Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,788 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

BFSP1
NM_001195.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.34

Variant links:

Genes affected

BFSP1 (HGNC:1040): (beaded filament structural protein 1) This gene encodes a lens-specific intermediate filament-like protein named filensin. The encoded protein is expressed in lens fiber cells after differentiation has begun. This protein functions as a component of the beaded filament which is a cytoskeletal structure found in lens fiber cells. Mutations in this gene are the cause of autosomal recessive cortical juvenile-onset cataract. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

BFSP1 links:

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ACMG classification

Classification made for transcript

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 rank	MANE	Protein	UniProt
BFSP1	NM_001195.5 link	c.1943C>T	p.Thr648Ile	missense_variant	Exon 8 of 8	ENST00000377873.8	NP_001186.1	Q12934-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
BFSP1	ENST00000377873.8 link	c.1943C>T	p.Thr648Ile	missense_variant	Exon 8 of 8	1	NM_001195.5	ENSP00000367104.3	Q12934-1
BFSP1	ENST00000377868.6 link	c.1568C>T	p.Thr523Ile	missense_variant	Exon 8 of 8	1		ENSP00000367099.2	Q12934-2
BFSP1	ENST00000536626.7 link	c.1526C>T	p.Thr509Ile	missense_variant	Exon 9 of 9	2		ENSP00000442522.1	Q12934-3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251314

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135832

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461788

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727188

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000895

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.:

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cataract 33

Uncertain:1

Feb 17, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. This variant has not been reported in the literature in individuals with BFSP1-related conditions. This sequence change replaces threonine with isoleucine at codon 648 of the BFSP1 protein (p.Thr648Ile). The threonine residue is highly conserved and there is a moderate physicochemical difference between threonine and isoleucine. This variant is present in population databases (rs752902567, ExAC 0.03%). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.83

BayesDel_addAF

Uncertain

0.098

BayesDel_noAF

Uncertain

0.13

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.66

D;.;.

Eigen

Pathogenic

0.79

Eigen_PC

Pathogenic

0.74

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Benign

0.85

T;T;T

M_CAP

Uncertain

0.19

MetaRNN

Uncertain

0.57

D;D;D

MetaSVM

Uncertain

-0.057

MutationAssessor

Uncertain

2.5

M;.;.

PrimateAI

Uncertain

0.62

PROVEAN

Uncertain

-3.2

D;D;D

REVEL

Uncertain

0.48

Sift

Pathogenic

0.0

D;D;D

Sift4G

Pathogenic

0.0

D;.;D

Polyphen

1.0

D;D;.

Vest4

0.51

MVP

0.89

MPC

0.44

ClinPred

0.96

GERP RS

5.0

Varity_R

0.60

gMVP

0.61

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over