5-128357393-T-A

Variant names:

• chr5-128357393-T-A
• rs148598779
• NM_001999.4:c.2557A>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM2 BP4_Moderate BS2

The NM_001999.4(FBN2):​c.2557A>T​(p.Ile853Leu) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,532 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I853V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: FBN2 NM_001999.4 missense, splice_region
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.692
• Publications: 3 publications found

Genes affected

FBN2 (HGNC:3604): (fibrillin 2) The protein encoded by this gene is a component of connective tissue microfibrils and may be involved in elastic fiber assembly. Mutations in this gene cause congenital contractural arachnodactyly. [provided by RefSeq, Jul 2008]

FBN2 Gene-Disease associations (from GenCC):

• congenital contractural arachnodactyly

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Orphanet
• carpal tunnel syndrome

  Inheritance: AD Classification: LIMITED Submitted by: Franklin by Genoox
• macular degeneration, early-onset

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: Unknown Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.19596562).
• BS2: High AC in GnomAdExome4 at 5 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001999.4. 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
	FBN2	NM_001999.4	MANE Select	c.2557A>T	p.Ile853Leu	missense splice_region	Exon 20 of 65	NP_001990.2	P35556-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBN2	ENST00000262464.9	TSL:1 MANE Select	c.2557A>T	p.Ile853Leu	missense splice_region	Exon 20 of 65	ENSP00000262464.4	P35556-1
	FBN2	ENST00000939405.1		c.2458A>T	p.Ile820Leu	missense splice_region	Exon 19 of 64	ENSP00000609464.1
	FBN2	ENST00000939404.1		c.2404A>T	p.Ile802Leu	missense splice_region	Exon 19 of 64	ENSP00000609463.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251290 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461532 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727070

African (AFR) AF: 0.00 AC: 0 AN: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.0000749 AC: 4 AN: 53410

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111734

Other (OTH) AF: 0.00 AC: 0 AN: 60382

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.0000165 AC: 2

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.043	T
BayesDel_noAF	Benign	-0.18
CADD	Benign	20
DANN	Benign	0.96
DEOGEN2	Uncertain	0.51	D
Eigen	Benign	-0.54
Eigen_PC	Benign	-0.45
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Benign	0.83	T
M_CAP	Benign	0.049	D
MetaRNN	Benign	0.20	T
MetaSVM	Uncertain	-0.10	T
MutationAssessor	Uncertain	2.1	M
PhyloP100		0.69
PrimateAI	Benign	0.39	T
PROVEAN	Benign	-1.6	N
REVEL	Benign	0.27
Sift	Uncertain	0.0070	D
Sift4G	Uncertain	0.012	D
Polyphen		0.0010	B
Vest4		0.38
MutPred		0.47		Gain of catalytic residue at I853 (P = 0.2022)
MVP		0.63
MPC		0.38
ClinPred		0.37	T
GERP RS		-0.12
Varity_R		0.15
gMVP		0.60
Mutation Taster		=83/17	polymorphism

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

Other links and lift over

dbSNP: rs148598779; hg19: chr5-127693085;