A recurrent fibrillin-1 mutation in severe early onset Marfan syndrome

J Pediatr Genet. 2014 Sep;3(3):157-62. doi: 10.3233/PGE-14095.

Abstract

The recurrent substitution of isoleucine for threonine at codon 1048 (I1048T) substitution has been linked to severe, early onset Marfan syndrome, however, the existence of strong genotype-phenotype associations in Marfan syndrome (MFS) is not widely agreed upon. Our aim is to substantiate the association between the I1048T substitution and a severe clinical presentation to facilitate care planning and genetic counseling. We review the clinical findings from seven cases of early-onset MFS with a recurrent I1048T substitution. The presented findings include those from one newly diagnosed case, significant new detail from three additional cases, and a review of published findings in three cases. All seven individuals with the I1048T substitution had mitral insufficiency, arachnodactyly and characteristic facies consistent with early-onset MFS. Our findings support the existence of a genotype-phenotype correlation between the I1048T substitution and early-onset MFS. Recognition of this relationship has implications for genetic counseling and clinical care. Additionally, exploration of how the I1048T substitution results in a severe phenotype may lead to further insight into the pathophysiology of MFS.

Keywords: FBN1; Marfan syndrome; genotype-phenotype correlation; severe early onset.