rs137854472

chr15-48488448-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM1 PP2 BP4 BP6

The NM_000138.5(FBN1):c.3128A>G(p.Lys1043Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000479 in 1,461,850 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K1043N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: FBN1 NM_000138.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1 B:1
• Conservation: PhyloP100: 3.95

Genes affected

FBN1 (HGNC:3603): (fibrillin 1) This gene encodes a member of the fibrillin family of proteins. The encoded preproprotein is proteolytically processed to generate two proteins including the extracellular matrix component fibrillin-1 and the protein hormone asprosin. Fibrillin-1 is an extracellular matrix glycoprotein that serves as a structural component of calcium-binding microfibrils. These microfibrils provide force-bearing structural support in elastic and nonelastic connective tissue throughout the body. Asprosin, secreted by white adipose tissue, has been shown to regulate glucose homeostasis. Mutations in this gene are associated with Marfan syndrome and the related MASS phenotype, as well as ectopia lentis syndrome, Weill-Marchesani syndrome, Shprintzen-Goldberg syndrome and neonatal progeroid syndrome. [provided by RefSeq, Apr 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 9 uncertain in NM_000138.5
• PP2: Missense variant where missense usually causes diseases, FBN1
• BP4: Computational evidence support a benign effect (MetaRNN=0.3638907).
• BP6: Variant 15-48488448-T-C is Benign according to our data. Variant chr15-48488448-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 16446.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBN1	NM_000138.5	c.3128A>G	p.Lys1043Arg	missense_variant	26/66	ENST00000316623.10
FBN1	NM_001406716.1	c.3128A>G	p.Lys1043Arg	missense_variant	25/65

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBN1	ENST00000316623.10	c.3128A>G	p.Lys1043Arg	missense_variant	26/66	1	NM_000138.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251474 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135912

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000109

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: 0.00000479 AC: 7 AN: 1461850 Hom.: 0 Cov.: 33 AF XY: 0.00000550 AC XY: 4 AN XY: 727228

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000176

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

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neonatal Marfan syndrome Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jan 01, 1997

- -

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 19, 2018

The p.K1043R variant (also known as c.3128A>G), located in coding exon 25 of the FBN1 gene, results from an A to G substitution at nucleotide position 3128. The lysine at codon 1043 is replaced by arginine, an amino acid with highly similar properties. This alteration has been reported in a neonatal Marfan syndrome case; however, it has also been detected in a mitochondrial cytopathy individual and her healthy mother (Wang M et al. Hum. Mutat. 1997;9:359-62; Kohda M et al. PLoS Genet. 2016;12:e1005679). This amino acid position is not well conserved in available vertebrate species, and arginine is the reference amino acid in other vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jun 27, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.086
BayesDel_addAF	Uncertain	0.012	T
BayesDel_noAF	Uncertain	0.010
Cadd	Uncertain	24
Dann	Uncertain	0.99
Eigen	Benign	-0.36
Eigen_PC	Benign	-0.035
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.66	T
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.36	T
MetaSVM	Benign	-0.32	T
MutationTaster	Benign	1.0	A
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-0.44	N
REVEL	Uncertain	0.40
Sift	Benign	0.70	T
Sift4G	Benign	1.0	T
Vest4		0.30
MutPred		0.80		Loss of methylation at K1043 (P = 0.0075);
MVP		0.91
MPC		0.45
ClinPred		0.25	T
GERP RS		6.2

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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

Other links and lift over

dbSNP: rs137854472; hg19: chr15-48780645;