Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_ModeratePM2PP5_Moderate
The NM_000501.4(ELN):c.1918+1G>A variant causes a splice donor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).
ELN (HGNC:3327): (elastin) This gene encodes a protein that is one of the two components of elastic fibers. Elastic fibers comprise part of the extracellular matrix and confer elasticity to organs and tissues including the heart, skin, lungs, ligaments, and blood vessels. The encoded protein is rich in hydrophobic amino acids such as glycine and proline, which form mobile hydrophobic regions bounded by crosslinks between lysine residues. Degradation products of the encoded protein, known as elastin-derived peptides or elastokines, bind the elastin receptor complex and other receptors and stimulate migration and proliferation of monocytes and skin fibroblasts. Elastokines can also contribute to cancer progression. Deletions and mutations in this gene are associated with supravalvular aortic stenosis (SVAS) and autosomal dominant cutis laxa. [provided by RefSeq, Aug 2017]
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.027586207 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.3, offset of 17, new splice context is: gagGTggga. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-74063370-G-A is Pathogenic according to our data. Variant chr7-74063370-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 163398.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr7-74063370-G-A is described in Lovd as [Pathogenic].
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The 1918+1G>A variant in ELN has not been reported in the literature nor previou sly identified by our laboratory. This variant occurs in the invariant region (+ /- 1, 2) of the splice consensus sequence and is predicted to cause altered spli cing leading to an abnormal or absent protein. Loss of function of the ELN gene is an established mechanism of disease in SVAS (Human Gene Mutation Database, HG MD). In summary, 1918+1G>A variant meets out pathogenicity criteria (http://pcpg m.partners.org/lmm). -