NM_000088.4:c.1042G>A
Variant summary
Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP6BS2
The NM_000088.4(COL1A1):c.1042G>A(p.Ala348Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000451 in 1,588,628 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000088.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -4 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
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COL1A1 | NM_000088.4 | c.1042G>A | p.Ala348Thr | missense_variant | Exon 16 of 51 | ENST00000225964.10 | NP_000079.2 | |
COL1A1 | XM_005257058.5 | c.1042G>A | p.Ala348Thr | missense_variant | Exon 16 of 49 | XP_005257115.2 | ||
COL1A1 | XM_011524341.2 | c.957+377G>A | intron_variant | Intron 14 of 47 | XP_011522643.1 | |||
COL1A1 | XM_005257059.5 | c.957+377G>A | intron_variant | Intron 14 of 37 | XP_005257116.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000210 AC: 32AN: 152030Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.000129 AC: 27AN: 209234Hom.: 0 AF XY: 0.000125 AC XY: 14AN XY: 111810
GnomAD4 exome AF: 0.000476 AC: 684AN: 1436598Hom.: 0 Cov.: 33 AF XY: 0.000466 AC XY: 332AN XY: 711872
GnomAD4 genome AF: 0.000210 AC: 32AN: 152030Hom.: 0 Cov.: 32 AF XY: 0.000148 AC XY: 11AN XY: 74266
ClinVar
Submissions by phenotype
not provided Uncertain:4
Identified in two patients with thoracic aortic aneurysm and dissection (TAAD) in published literature, however, one individual also harbored a pathogenic variant in the FBN1 gene (PMID: 29543232); Occurs in the triple helical domain at the X position in the canonical Gly-X-Y repeat; although this variant may have an effect on normal protein folding and function, missense substitution at the X position is not a common mechanism of disease (HGMD); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 29543232) -
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The COL1A1 c.1042G>A; p.Ala348Thr variant (rs139955975) is reported in the literature in two individuals affected with thoracic aortic aneurysm or dissection (Weerakkody 2018). This variant is reported in ClinVar (Variation ID: 35897) and is found in the non-Finnish European population with an allele frequency of 0.028% (30/107,172 alleles) in the Genome Aggregation Database. Computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.329). While this variant occurs in the Gly-X-Y triple helix repeat domain, it does not alter a conserved glycine reside like the majority of disease-causing missense variants (Amor Ben 2011). Due to limited information, the clinical significance of this variant is uncertain at this time. References: Ben Amor I et al. Genotype-phenotype correlations in autosomal dominant osteogenesis imperfecta. J Osteoporos. 2011; 2011:540178. PMID: 21912751 Weerakkody R et al. Targeted genetic analysis in a large cohort of familial and sporadic cases of aneurysm or dissection of the thoracic aorta. Genet Med. 2018 Nov;20(11):1414-1422. PMID: 29543232. -
Osteogenesis imperfecta Uncertain:2
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
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Osteogenesis imperfecta type I Uncertain:1Benign:1
This variant has been reported in an individual presenting with aneurysm. This COL1A1 variant (rs139955975) is rare (<0.1%) in a large population dataset (gnomAD: 33/240566 total alleles; 0.01%; no homozygotes), and has been reported in ClinVar. Three bioinformatic tools queried predict that this substitution would be tolerated, and the alanine residue at this position is evolutionarily conserved across mammals. We consider the clinical significance of c.1042G>A to be uncertain at this time. -
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Familial thoracic aortic aneurysm and aortic dissection Pathogenic:1
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Ehlers-Danlos syndrome Uncertain:1
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COL1A1-related disorder Uncertain:1
The COL1A1 c.1042G>A variant is predicted to result in the amino acid substitution p.Ala348Thr. This variant was previously reported in a cohort of individuals with aneurysm or dissection of the thoracic aorta (Weerakkody et al. 2018. PubMed ID: 2954332). This variant is reported in 0.028% of alleles in individuals of European (Non-Finnish) descent in gnomAD. However, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Ehlers-Danlos syndrome, arthrochalasia type Uncertain:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Infantile cortical hyperostosis Uncertain:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Cardiovascular phenotype Uncertain:1
The p.A348T variant (also known as c.1042G>A), located in coding exon 16 of the COL1A1 gene, results from a G to A substitution at nucleotide position 1042. The alanine at codon 348 is replaced by threonine, an amino acid with similar properties. This variant was reported in two individuals with thoracic aortic aneurysm or dissection (Weerakkody R et al. Genet. Med., 2018 11;20:1414-1422). This alteration has also been noted in a biobank cohort (Wright CF et al. Am J Hum Genet, 2019 Feb;104:275-286). 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. -
not specified Benign:1
Variant summary: COL1A1 c.1042G>A (p.Ala348Thr) results in a non-conservative amino acid change located in the Collagen triple helix repeat of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00013 in 209234 control chromosomes. The observed variant frequency is approximately 5 fold of the estimated maximal expected allele frequency for a pathogenic variant in COL1A1 causing Osteogenesis Imperfecta phenotype (2.8e-05). To our knowledge, no occurrence of c.1042G>A in individuals affected with Osteogenesis Imperfecta and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 35897). Based on the evidence outlined above, the variant was classified as likely benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at