Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP3BS2
The NM_000501.4(ELN):c.1993+4A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000805 in 1,613,920 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).
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]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
In summary, this is a rare intronic change with uncertain impact on splicing. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of sequence changes on mRNA splicing suggest that this variant may alter RNA splicing, but this prediction has not been confirmed by published transcriptional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a ELN-related disease. This variant affects a nucleotide within the consensus splice site of intron 30. The majority of introns (70-73%) have an adenine at this position (PMID: 9536098). -