rs774851476

chr15-48481723-G-A

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 3P and 16B. PM1 PP2 BP6_Very_Strong BS1 BS2

The NM_000138.5(FBN1):c.3896C>T(p.Thr1299Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000626 in 1,613,562 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. T1299T) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000064 (0 hom.)
• Consequence: FBN1 NM_000138.5 missense
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:13
• Conservation: PhyloP100: 8.05

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 Benign. Variant got -13 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 5 uncertain in NM_000138.5
• PP2: Missense variant where missense usually causes diseases, FBN1
• BP6: Variant 15-48481723-G-A is Benign according to our data. Variant chr15-48481723-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 316375.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-48481723-G-A is described in Lovd as [Likely_benign].
• BS1: Variant frequency is greater than expected in population amr. gnomad4_exome allele frequency = 0.0000643 (94/1461540) while in subpopulation AMR AF= 0.00177 (79/44722). AF 95% confidence interval is 0.00145. There are 0 homozygotes in gnomad4_exome. There are 39 alleles in male gnomad4_exome subpopulation. Median coverage is 30. This position pass quality control queck.
• BS2: High AC in GnomAd at 7 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBN1	NM_000138.5	c.3896C>T	p.Thr1299Met	missense_variant	32/66	ENST00000316623.10
FBN1	NM_001406716.1	c.3896C>T	p.Thr1299Met	missense_variant	31/65

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBN1	ENST00000316623.10	c.3896C>T	p.Thr1299Met	missense_variant	32/66	1	NM_000138.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152022 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000459

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: 0.00

GnomAD3 exomes AF: 0.000294 AC: 74 AN: 251336 Hom.: 0 AF XY: 0.000214 AC XY: 29 AN XY: 135824

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00208

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000643 AC: 94 AN: 1461540 Hom.: 0 Cov.: 30 AF XY: 0.0000536 AC XY: 39 AN XY: 727092

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00177

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000989

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152022 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74244

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000459

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: 0.00

Alfa AF: 0.0000109 Hom.: 0

Bravo AF: 0.0000604

ExAC AF: 0.000247 AC: 30

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:13

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Benign:3

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Jun 17, 2020	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jun 05, 2018	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -
Likely benign, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Aug 28, 2019	- -

not specified Benign:2

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 25, 2018	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Feb 13, 2023	- -

Marfan syndrome Benign:2

Likely benign, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Jan 11, 2024	- -
Likely benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Stiff skin syndrome Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Weill-Marchesani syndrome Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Geleophysic dysplasia Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Acromicric dysplasia Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

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

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 22, 2024

- -

Ectopia lentis 1, isolated, autosomal dominant Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.34
BayesDel_addAF	Uncertain	0.053	T
BayesDel_noAF	Pathogenic	0.30
Cadd	Pathogenic	32
Dann	Pathogenic	1.0
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.80	D
MetaRNN	Uncertain	0.62	D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-5.1	D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Vest4		0.74
MutPred		0.71		Loss of methylation at K1300 (P = 0.0416);
MVP		0.94
MPC		1.4
ClinPred		0.19	T
GERP RS		5.4

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs774851476; hg19: chr15-48773920;