chr5-128335997-C-A

Variant names:

• chr5-128335997-C-A
• rs778784375
• NM_001999.4:c.3715G>T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_001999.4(FBN2):​c.3715G>T​(p.Gly1239Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1239V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FBN2 NM_001999.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.17
• Publications: 1 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: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 5 benign, 10 uncertain in NM_001999.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.802

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.3715G>T	p.Gly1239Cys	missense	Exon 28 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.3715G>T	p.Gly1239Cys	missense	Exon 28 of 65	ENSP00000262464.4	P35556-1
	FBN2	ENST00000939405.1		c.3616G>T	p.Gly1206Cys	missense	Exon 27 of 64	ENSP00000609464.1
	FBN2	ENST00000939404.1		c.3562G>T	p.Gly1188Cys	missense	Exon 27 of 64	ENSP00000609463.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.60
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.65	D
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.85	D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.80	D
MetaSVM	Uncertain	0.72	D
MutationAssessor	Uncertain	2.4	M
PhyloP100		2.2
PrimateAI	Uncertain	0.61	T
PROVEAN	Uncertain	-4.1	D
REVEL	Pathogenic	0.68
Sift	Benign	0.14	T
Sift4G	Benign	0.082	T
Polyphen		1.0	D
Vest4		0.75
MutPred		0.51		Gain of catalytic residue at T1241 (P = 0.0898)
MVP		0.68
MPC		0.88
ClinPred		0.99	D
GERP RS		3.8
Varity_R		0.79
gMVP		0.87
Mutation Taster		=35/65	disease causing

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: rs778784375; hg19: chr5-127671689;