rs750327890

Variant names:

• chr5-128332926-C-T
• rs750327890
• NM_001999.4:c.4208G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 6P and 2B. PM1 PM2 PP3_Moderate BP6_Moderate

The NM_001999.4(FBN2):​c.4208G>A​(p.Gly1403Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,616 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1403A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: FBN2 NM_001999.4 missense
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 7.91
• Publications: 2 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: PanelApp Australia, Orphanet, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
• carpal tunnel syndrome

  Inheritance: AD Classification: LIMITED Submitted by: Franklin by Genoox
• familial thoracic aortic aneurysm and aortic dissection

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

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 8 uncertain in NM_001999.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.932
• BP6: Variant 5-128332926-C-T is Benign according to our data. Variant chr5-128332926-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 528427.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN2	NM_001999.4	c.4208G>A	p.Gly1403Asp	missense_variant	Exon 32 of 65	ENST00000262464.9	NP_001990.2
FBN2	XM_017009228.3	c.4055G>A	p.Gly1352Asp	missense_variant	Exon 31 of 64		XP_016864717.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBN2	ENST00000262464.9	c.4208G>A	p.Gly1403Asp	missense_variant	Exon 32 of 65	1	NM_001999.4	ENSP00000262464.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251392 AF XY: 0.0000147

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: 0.00000137 AC: 2 AN: 1461616 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727108

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.0000447 AC: 2 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111818

Other (OTH) AF: 0.00 AC: 0 AN: 60386

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital contractural arachnodactyly Benign:1

Jun 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	D;.;D;T;T
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;.;.;D;D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D
MetaSVM	Pathogenic	0.84	D
MutationAssessor	Pathogenic	3.1	M;.;M;.;.
PhyloP100		7.9
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-6.6	D;.;D;D;D
REVEL	Pathogenic	0.89
Sift	Uncertain	0.0010	D;.;D;D;D
Sift4G	Uncertain	0.029	.;.;.;D;D
Polyphen		1.0	D;.;D;.;D
Vest4		0.93
MutPred		0.76		Gain of catalytic residue at G1403 (P = 0.0363);.;Gain of catalytic residue at G1403 (P = 0.0363);.;.;
MVP		0.85
MPC		0.99
ClinPred		0.98	D
GERP RS		4.8
Varity_R		0.81
gMVP		0.92
Mutation Taster		=14/86	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: rs750327890; hg19: chr5-127668618; COSMIC: COSV105107626;