11-62690369-AGGAACTAGAGCAGGTGGGGCGCTGTC-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_001122955.4(BSCL2):c.1361_1386del(p.Arg454LeufsTer16) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000684 in 1,461,756 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: BSCL2 NM_001122955.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.89

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:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0202 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-62690369-AGGAACTAGAGCAGGTGGGGCGCTGTC-A is Pathogenic according to our data. Variant chr11-62690369-AGGAACTAGAGCAGGTGGGGCGCTGTC-A is described in ClinVar as [Pathogenic]. Clinvar id is 947075.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BSCL2	NM_001122955.4	c.1361_1386del	p.Arg454LeufsTer16	frameshift_variant	11/11	ENST00000360796.10
HNRNPUL2-BSCL2	NR_037946.1	n.3881_3906del		non_coding_transcript_exon_variant	24/24

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BSCL2	ENST00000360796.10	c.1361_1386del	p.Arg454LeufsTer16	frameshift_variant	11/11	1	NM_001122955.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000239 AC: 6 AN: 251424 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135892

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000173

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: 0.00000684 AC: 10 AN: 1461756 Hom.: 0 AF XY: 0.00000550 AC XY: 4 AN XY: 727190

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000224

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.: 32

Alfa AF: 0.0000936 Hom.: 0

Bravo AF: 0.0000189

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Sep 25, 2023

This sequence change results in a frameshift in the BSCL2 gene (p.Arg390Leufs*16). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 9 amino acid(s) of the BSCL2 protein and extend the protein by 6 additional amino acid residues. This variant is present in population databases (rs779154593, gnomAD 0.02%). 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: 947075). This variant disrupts a region of the BSCL2 protein in which other variant(s) (p.Gln391*) have been determined to be pathogenic (PMID: 19226263, 24024128). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs779154593; hg19: chr11-62457841;