FREM2 and Feingold syndrome: 5914G>A in the second of 5 consecutive Calx-β domains, a splicing mutation IVS14+1G >A resulting in a stop codon at residue 2549, a substitution mutation c.6499C>T, and a deletion mutation c.15delG in FREM2 gene have been reported to be associated with a risk of FS in OMIM database [18, 19].