9-99128971-A-T
Variant summary
Our verdict is Benign. The variant received -11 ACMG points: 0P and 11B. BP4_ModerateBP6BS1BS2
The NM_004612.4(TGFBR1):c.214A>T(p.Ile72Leu) variant causes a missense change. The variant allele was found at a frequency of 0.000256 in 1,613,910 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I72V) has been classified as Uncertain significance.
Frequency
Consequence
NM_004612.4 missense
Scores
Clinical Significance
Conservation
Publications
- familial thoracic aortic aneurysm and aortic dissectionInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
- Loeys-Dietz syndromeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
- Loeys-Dietz syndrome 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia, Genomics England PanelApp, G2P
- multiple self-healing squamous epitheliomaInheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen
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ACMG classification
Our verdict: Benign. The variant received -11 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000191 AC: 29AN: 152198Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000199 AC: 50AN: 250904 AF XY: 0.000214 show subpopulations
GnomAD4 exome AF: 0.000263 AC: 384AN: 1461712Hom.: 0 Cov.: 31 AF XY: 0.000256 AC XY: 186AN XY: 727152 show subpopulations
GnomAD4 genome AF: 0.000191 AC: 29AN: 152198Hom.: 0 Cov.: 32 AF XY: 0.000175 AC XY: 13AN XY: 74348 show subpopulations
ClinVar
Submissions by phenotype
not provided Uncertain:3Benign:1
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This variant is associated with the following publications: (PMID: 26017485, 27153395) -
The TGFBR1 c.214A>T; p.Ile72Leu variant (rs111513627) is reported in the literature in several individuals affected with abdominal aortic aneurysm, bicuspid aortic valve, or a connective tissue disorder; however, its clinical significance was not demonstrated in these individuals (Bonachea 2014, van de Luijtgaarden 2015, Weerakkody 2016). In one family affected with aortic aneurysm, the p.Ile72Leu variant did not segregate with disease (van de Luijtgaarden 2015). This variant is found in the non-Finnish European population with an overall allele frequency of 0.03% (44/128734 alleles) in the Genome Aggregation Database. The isoleucine at codon 72 is highly conserved, but computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.351). Due to limited information, the clinical significance of the p.Ile72Leu variant is uncertain at this time. References: Bonachea EM et al. Use of a targeted, combinatorial next-generation sequencing approach for the study of bicuspid aortic valve. BMC Med Genomics. 2014 Sep 26;7:56. van de Luijtgaarden KM et al. First genetic analysis of aneurysm genes in familial and sporadic abdominal aortic aneurysm. Hum Genet. 2015 Aug;134(8):881-93. Weerakkody RA et al. Targeted next-generation sequencing makes new molecular diagnoses and expands genotype-phenotype relationship in Ehlers-Danlos syndrome. Genet Med. 2016 Nov;18(11):1119-1127. -
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Familial thoracic aortic aneurysm and aortic dissection Uncertain:1Benign:3
The p.I72L variant (also known as c.214A>T), located in coding exon 2 of the TGFBR1 gene, results from an A to T substitution at nucleotide position 214. The isoleucine at codon 72 is replaced by leucine, an amino acid with highly similar properties. This alteration has been detected in abdominal aortic aneurysm (AAA) and connective tissue disease cohorts, but was reported not to segregate with AAA in at least one family (van de Luijtgaarden KM et al. Hum. Genet., 2015 Aug;134:881-93; Weerakkody RA et al. Genet. Med., 2016 11;18:1119-1127). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
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not specified Uncertain:1Benign:1
Variant classified as Uncertain Significance - Favor Benign. The Ile72Leu varian t in TGFBR1 has not been reported in individuals with clinical features of Loeys -Dietz syndrome, but has been identified in 0.1% (1/1126) of chromosomes from a clinically and racially unspecified population, and in 0.03% (3/8600) of Europea n American chromosomes by the NHLBI Exome Sequencing Project (http://evs.gs.wash ington.edu/EVS/; dbSNP rs111513627). While this frequency suggests that this var iant is more likely benign, it is too low to confidently rule out a disease caus ing role. Computational analyses (biochemical amino acid properties, conservatio n, AlignGVGD, PolyPhen2, and SIFT) do not provide strong support for or against an impact to the protein. In summary, additional information is needed to fully assess the clinical significance of the Ile72Leu variant. -
Variant summary: TGFBR1 c.214A>T (p.Ile72Leu) results in a conservative amino acid change located in the Activin types I and II receptor domain (IPR000472) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0002 in 250904 control chromosomes, predominantly at a frequency of 0.00036 within the Non-Finnish European subpopulation in the gnomAD database. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 290-fold of the estimated maximal expected allele frequency for a pathogenic variant in TGFBR1 causing Aortopathy phenotype (1.3e-06), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. c.214A>T has been reported in the literature in individuals affected with bicuspid aortic valve and unspecified connective tissue disease (Bonachea_2014, Weerakkody_2016), as well as abdominal aortic aneurysm in which the variant did not segregate in 1 family (van de Luijtgaarden_2015). These reports do not provide unequivocal conclusions about association of the variant with Aortopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Nine submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Multiple submitters reported the variant with conflicting assessments. Based on the evidence outlined above, the variant was classified as likely benign. -
Ehlers-Danlos syndrome Uncertain:1
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TGFBR1-related disorder Uncertain:1
The TGFBR1 c.214A>T variant is predicted to result in the amino acid substitution p.Ile72Leu. This variant was reported as a variant of uncertain significance in two individuals with abdominal aortic aneurysms (van de Luijtgaarden et al. 2015. PubMed ID: 26017485) and in an individual with unspecified hereditary connective tissue disorder (Weerakkody et al. 2016. PubMed ID: 27011056). This variant resides outside of the serine-threonine kinase domain, which contains the majority of pathogenic missense variants (amino acids 206-496; Wrana et al. 1994. PubMed ID: 8047140). This variant is reported in 0.034% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/9-101891253-A-T) and has conflicting interpretations of likely benign and uncertain significance in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/178136/). Although we suspect this variant is more likely to be benign, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at