rs138303817

Positions:

• chr5-128338081-C-A
• chr5-128338081-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2 PP2 PP3_Strong PP5_Moderate

The NM_001999.4(FBN2):​c.3514G>T​(p.Gly1172Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1172S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: FBN2 NM_001999.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.91

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), FBN2. . Gene score misZ 1.5491 (greater than the threshold 3.09). Trascript score misZ 3.2752 (greater than threshold 3.09). GenCC has associacion of gene with familial thoracic aortic aneurysm and aortic dissection, carpal tunnel syndrome, macular degeneration, early-onset, congenital contractural arachnodactyly.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.949
• PP5: Variant 5-128338081-C-A is Pathogenic according to our data. Variant chr5-128338081-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 487464.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBN2	NM_001999.4	c.3514G>T	p.Gly1172Cys	missense_variant	27/65	ENST00000262464.9
FBN2	XM_017009228.3	c.3361G>T	p.Gly1121Cys	missense_variant	26/64

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBN2	ENST00000262464.9	c.3514G>T	p.Gly1172Cys	missense_variant	27/65	1	NM_001999.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital contractural arachnodactyly Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Center for Genomics, Ann and Robert H. Lurie Children's Hospital of Chicago

Aug 01, 2017

FBN2 NM_001999.3 exon27 p.Gly1172Cys (c.3514G>T): This variant has not been reported in the literature, but has been identified de novo by our laboratory in 1 individual with clinical features of Marfan related disorders. This variant is not present in large control databases. Evolutionary conservation and computational predictive tools suggest that this variant may impact the protein. In summary, data on this variant is highly suspicious for disease, but requires further evidence for pathogenicity. Therefore, this variant classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D;.;D;D;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.97	D;.;.;D;D
M_CAP	Pathogenic	0.46	D
MetaRNN	Pathogenic	0.95	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	H;.;H;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.80	D
PROVEAN	Pathogenic	-8.2	D;.;D;D;D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D;.;D;D;D
Sift4G	Uncertain	0.0020	.;.;.;D;D
Polyphen		1.0	D;.;D;.;D
Vest4		0.97
MutPred		0.64		Loss of glycosylation at T1173 (P = 0.1558);.;Loss of glycosylation at T1173 (P = 0.1558);.;.;
MVP		0.91
MPC		0.89
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.99
gMVP		0.95

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs138303817; hg19: chr5-127673773;