rs191989961

Variant names:

• chr15-48474614-C-T
• rs191989961
• NM_000138.5:c.4001G>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 3P and 8B. PM1 PP2 BP4_Strong BS1

The NM_000138.5(FBN1):​c.4001G>A​(p.Gly1334Asp) variant causes a missense change. The variant allele was found at a frequency of 0.0000155 in 1,614,094 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). The gene FBN1 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: 𝑓 0.00013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: FBN1 NM_000138.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8 B:2
• Conservation: PhyloP100: 6.21
• Publications: 3 publications found

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]

FBN1 Gene-Disease associations (from GenCC):

• Marfan syndrome

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, ClinGen, Orphanet, Genomics England PanelApp
• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: Unknown, AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Acromicric dysplasia

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet
• progeroid and marfanoid aspect-lipodystrophy syndrome

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae)
• stiff skin syndrome

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• Weill-Marchesani syndrome 2, dominant

  Inheritance: AD Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• geleophysic dysplasia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• isolated ectopia lentis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• neonatal Marfan syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Weill-Marchesani syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• ectopia lentis 1, isolated, autosomal dominant

  Inheritance: AD Classification: LIMITED Submitted by: G2P
• Shprintzen-Goldberg syndrome

  Inheritance: Unknown, AD Classification: LIMITED, NO_KNOWN Submitted by: Labcorp Genetics (formerly Invitae), ClinGen

ACMG classification

Specifications for FBN1 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Likely_benign. The variant received -5 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 10 uncertain in NM_000138.5
• PP2: Missense variant in the FBN1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 1311 curated pathogenic missense variants (we use a threshold of 10). The gene has 112 curated benign missense variants. Gene score misZ: 5.0644 (above the threshold of 3.09). Trascript score misZ: 8.1787 (above the threshold of 3.09). GenCC associations: The gene is linked to Weill-Marchesani syndrome 2, dominant, Acromicric dysplasia, isolated ectopia lentis, progeroid and marfanoid aspect-lipodystrophy syndrome, Marfan syndrome, stiff skin syndrome, Shprintzen-Goldberg syndrome, familial thoracic aortic aneurysm and aortic dissection, ectopia lentis 1, isolated, autosomal dominant, Weill-Marchesani syndrome, neonatal Marfan syndrome, geleophysic dysplasia.
• BP4: Computational evidence support a benign effect (MetaRNN=0.044210315).
• BS1: Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000131 (20/152248) while in subpopulation AMR AF = 0.00111 (17/15286). AF 95% confidence interval is 0.000708. There are 0 homozygotes in GnomAd4. There are 9 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000138.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBN1	NM_000138.5	MANE Select	c.4001G>A	p.Gly1334Asp	missense	Exon 33 of 66	NP_000129.3
	FBN1	NM_001406716.1		c.4001G>A	p.Gly1334Asp	missense	Exon 32 of 65	NP_001393645.1	P35555

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBN1	ENST00000316623.10	TSL:1 MANE Select	c.4001G>A	p.Gly1334Asp	missense	Exon 33 of 66	ENSP00000325527.5	P35555
	FBN1	ENST00000559133.6	TSL:1	n.4001G>A		non_coding_transcript_exon	Exon 33 of 67	ENSP00000453958.2	H0YND0
	FBN1	ENST00000537463.6	TSL:5	n.673G>A		non_coding_transcript_exon	Exon 8 of 31	ENSP00000440294.2	F6U495

Frequencies

GnomAD3 genomes AF: 0.000131 AC: 20 AN: 152130 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00111

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: 0.00143

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251238 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000342 AC: 5 AN: 1461846 Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3 AN XY: 727228

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000671 AC: 3 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53408

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111988

Other (OTH) AF: 0.0000331 AC: 2 AN: 60394

GnomAD4 genome AF: 0.000131 AC: 20 AN: 152248 Hom.: 0 Cov.: 32 AF XY: 0.000121 AC XY: 9 AN XY: 74436

African (AFR) AF: 0.00 AC: 0 AN: 41542

American (AMR) AF: 0.00111 AC: 17 AN: 15286

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5180

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10604

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68016

Other (OTH) AF: 0.00142 AC: 3 AN: 2114

Alfa AF: 0.000343 Hom.: 0

Bravo AF: 0.000268

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	1	Familial thoracic aortic aneurysm and aortic dissection (2)
-	2	-	FBN1-related disorder (2)
-	2	-	Marfan syndrome (2)
-	2	-	not specified (2)
-	1	-	Marfan syndrome;C0265287:Acromicric dysplasia;C1858556:MASS syndrome;C1861456:Stiff skin syndrome;C1869115:Weill-Marchesani syndrome 2, dominant;C3280054:Geleophysic dysplasia 2;C3541518:Ectopia lentis 1, isolated, autosomal dominant;C4310796:Progeroid and marfanoid aspect-lipodystrophy syndrome (1)
-	-	1	Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.075
BayesDel_addAF	Benign	-0.037	T
BayesDel_noAF	Benign	-0.29
CADD	Benign	18
DANN	Uncertain	1.0
Eigen	Benign	-0.54
Eigen_PC	Benign	-0.26
FATHMM_MKL	Benign	0.56	D
LIST_S2	Benign	0.81	T
M_CAP	Uncertain	0.19	D
MetaRNN	Benign	0.044	T
MetaSVM	Benign	-0.69	T
PhyloP100		6.2
PrimateAI	Benign	0.42	T
PROVEAN	Benign	3.8	N
REVEL	Uncertain	0.30
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Vest4		0.23
MVP		0.33
MPC		0.65
ClinPred		0.48	T
GERP RS		3.9
Mutation Taster		=68/32	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs191989961; hg19: chr15-48766811;