chr11-65539073-GGCGGCGTCA-G

Position:

• chr11-65539073-GGCGGCGTCA-G

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_001130144.3(LTBP3):​c.3910_*6del variant causes a stop lost, 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000408 in 1,224,798 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: LTBP3 NM_001130144.3 stop_lost, 3_prime_UTR
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 2.85

Genes affected

LTBP3 (HGNC:6716): (latent transforming growth factor beta binding protein 3) The protein encoded by this gene forms a complex with transforming growth factor beta (TGF-beta) proteins and may be involved in their subcellular localization. Activation of this complex requires removal of the encoded binding protein. This protein also may play a structural role in the extracellular matrix. Three transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Jan 2010]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PVS1: Stoplost variant. No alternative stopcodon identified downstream, so we assume a Nonstop Mediated Decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-65539073-GGCGGCGTCA-G is Pathogenic according to our data. Variant chr11-65539073-GGCGGCGTCA-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 422699.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LTBP3	NM_001130144.3	c.3910_*6del		stop_lost, 3_prime_UTR_variant	28/28	ENST00000301873.11	NP_001123616.1
LTBP3	NM_001164266.1	c.3418_*6del		stop_lost, 3_prime_UTR_variant	27/27		NP_001157738.1
LTBP3	NM_021070.4	c.3769_*6del		stop_lost, 3_prime_UTR_variant	27/27		NP_066548.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LTBP3	ENST00000301873.11	c.3910_*6del		stop_lost, 3_prime_UTR_variant	28/28	2	NM_001130144.3	ENSP00000301873	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000408 AC: 5 AN: 1224798 Hom.: 0 AF XY: 0.00000671 AC XY: 4 AN XY: 596490

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000501

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Sep 02, 2020

Not observed in large population cohorts (Lek et al., 2016); Normal stop codon changed to an Arginine codon, leading to the addition of 9 amino acids at the C-terminus; Has not been previously published as pathogenic or benign to our knowledge -

Brachyolmia-amelogenesis imperfecta syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 26, 2023

This sequence change disrupts the translational stop signal of the LTBP3 mRNA. It is expected to extend the length of the LTBP3 protein by 9 additional amino acid residues. This variant is not present in population databases (gnomAD no frequency). 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. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. ClinVar contains an entry for this variant (Variation ID: 422699). This variant has not been reported in the literature in individuals affected with LTBP3-related conditions. -

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: rs779871744; hg19: chr11-65306544;