rs1013079991

Positions:

• chr11-62692475-T-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001122955.4(BSCL2):​c.766-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.000000684 in 1,461,452 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BSCL2 NM_001122955.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1 U:1 O:1
• Conservation: PhyloP100: 6.56

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]

HNRNPUL2-BSCL2 (HGNC:49189): (HNRNPUL2-BSCL2 readthrough (NMD candidate)) This locus represents naturally occurring read-through transcription between the neighboring HNRNPUL2 (heterogeneous nuclear ribonucleoprotein U-like 2) and BSCL2 (Berardinelli-Seip congenital lipodystrophy 2 (seipin)) genes on chromosome 11. The read-through transcript is a candidate for nonsense-mediated mRNA decay (NMD), and is unlikely to produce a protein product. [provided by RefSeq, Mar 2011]

BSCL2 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-62692475-T-C is Pathogenic according to our data. Variant chr11-62692475-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 372117.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr11-62692475-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BSCL2	NM_001122955.4	c.766-2A>G		splice_acceptor_variant, intron_variant		ENST00000360796.10	NP_001116427.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BSCL2	ENST00000360796.10	c.766-2A>G		splice_acceptor_variant, intron_variant		1	NM_001122955.4	ENSP00000354032.5
HNRNPUL2-BSCL2	ENST00000403734.2	n.*817-2A>G		splice_acceptor_variant, intron_variant		2		ENSP00000456010.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461452 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726990

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital generalized lipodystrophy type 2 Pathogenic:1 Other:1

not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 04, 2022	- -

Berardinelli-Seip congenital lipodystrophy Uncertain:1

Uncertain significance, no assertion criteria provided

literature only

Inherited Neuropathy Consortium Ii, University Of Miami

Jan 06, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Uncertain	0.050
CADD	Uncertain	25
DANN	Uncertain	0.99
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		5.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.89
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AL_spliceai		1.0		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1013079991; hg19: chr11-62459947;