rs147314661

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1PM2

The NM_001122955.4(BSCL2):c.299G>T(p.Cys100Phe) variant causes a missense change. The variant allele was found at a frequency of 0.0000366 in 1,614,106 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C100Y) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00021 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000018 ( 1 hom. )

Consequence

BSCL2
NM_001122955.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 6.65

Variant links:

Genes affected

BSCL2 (HGNC:15832): (BSCL2 lipid droplet biogenesis associated, seipin) This gene encodes the multi-pass transmembrane protein protein seipin. This protein localizes to the endoplasmic reticulum and may be important for lipid droplet morphology. Mutations in this gene have been associated with congenital generalized lipodystrophy type 2 or Berardinelli-Seip syndrome, a rare autosomal recessive disease characterized by a near absence of adipose tissue and severe insulin resistance. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. Naturally occurring read-through transcription occurs between this locus and the neighboring locus HNRNPUL2 (heterogeneous nuclear ribonucleoprotein U-like 2).[provided by RefSeq, Mar 2011]

BSCL2 links:

HNRNPUL2-BSCL2 (HGNC:):

HNRNPUL2-BSCL2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM1

In a topological_domain Lumenal (size 194) in uniprot entity BSCL2_HUMAN there are 20 pathogenic changes around while only 5 benign (80%) in NM_001122955.4

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BSCL2	NM_001122955.4 linkuse as main transcript	c.299G>T	p.Cys100Phe	missense_variant	2/11	ENST00000360796.10
HNRNPUL2-BSCL2	NR_037946.1 linkuse as main transcript	n.2819G>T		non_coding_transcript_exon_variant	15/24

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BSCL2	ENST00000360796.10 linkuse as main transcript	c.299G>T	p.Cys100Phe	missense_variant	2/11	1	NM_001122955.4	A2	Q96G97-4

Frequencies

GnomAD3 genomes

AF:

0.000210

AC:

AN:

152228

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00177

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:

0.00144

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251270

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135850

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

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:

0.000163

GnomAD4 exome

AF:

0.0000185

AC:

AN:

1461878

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

727238

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000402

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:

0.000149

GnomAD4 genome

AF:

0.000210

AC:

AN:

152228

Hom.:

Cov.:

AF XY:

0.000229

AC XY:

AN XY:

74374

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.00177

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:

0.00144

Bravo

AF:

0.000506

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 27, 2021

The c.107G>T (p.C36F) alteration is located in exon 2 (coding exon 1) of the BSCL2 gene. This alteration results from a G to T substitution at nucleotide position 107, causing the cysteine (C) at amino acid position 36 to be replaced by a phenylalanine (F). The heterozygous missense change is ultra rare in population databases:_x000D_ _x000D_ Based on data from the Genome Aggregation Database (gnomAD), the BSCL2 c.107G>T alteration was observed in <0.001% (2/277,084). A similar amino acid change has been observed in an affected individual: _x000D_ _x000D_ A similar missense change affecting the same amino acid c.107G>A (p.C36Y) was reported in a patient with spastic paraplegia mild mental retardation, and no amyotrophy (Ishiura, 2014). The altered amino acid is conserved throughout evolution:_x000D_ _x000D_ The p.C36 amino acid is highly conserved in available vertebrate species. In silico prediction is conflicting:_x000D_ _x000D_ The p.C36F alteration is predicted to be possibly damaging by Polyphen and tolerated by SIFT in silico analyses. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Charcot-Marie-Tooth disease type 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 07, 2023

This sequence change replaces cysteine, which is neutral and slightly polar, with phenylalanine, which is neutral and non-polar, at codon 36 of the BSCL2 protein (p.Cys36Phe). This variant is present in population databases (rs147314661, gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BSCL2-related conditions. ClinVar contains an entry for this variant (Variation ID: 246509). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BSCL2 protein function with a negative predictive value of 80%. 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. -

BSCL2-related disorder

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 06, 2023

The BSCL2 c.299G>T variant is predicted to result in the amino acid substitution p.Cys100Phe. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0085% of alleles in individuals of Latino descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Congenital generalized lipodystrophy type 2;C2931276:Hereditary spastic paraplegia 17;C4014700:Severe neurodegenerative syndrome with lipodystrophy;C5436838:Neuronopathy, distal hereditary motor, type 5C

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Apr 12, 2022

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 04, 2023

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 18790819) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.34

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.37

Cadd

Pathogenic

Dann

Benign

0.95

Eigen

Uncertain

0.22

Eigen_PC

Uncertain

0.30

FATHMM_MKL

Uncertain

0.97

LIST_S2

Benign

0.83

T;T;T;.;.;T;T;T;T;D

M_CAP

Uncertain

0.12

MetaRNN

Uncertain

0.69

D;D;D;D;D;D;D;D;D;D

MetaSVM

Uncertain

0.072

MutationTaster

Benign

1.0

D;D;D;D;D;D;D

PrimateAI

Uncertain

0.68

PROVEAN

Uncertain

-3.9

D;D;D;D;D;D;D;D;D;D

REVEL

Pathogenic

0.69

Sift

Benign

0.051

T;T;T;T;T;T;T;T;T;D

Sift4G

Benign

0.084

T;T;T;T;T;T;.;.;.;D

Polyphen

0.37, 0.96

.;B;.;D;D;D;.;.;.;.

Vest4

0.85

MVP

0.94

ClinPred

0.85

GERP RS

5.0

Varity_R

0.64

gMVP

0.62

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

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