Two novel mutations of FBN1 in Jordanian patients with Marfan syndrome.

Marfan syndrome is an autosomal dominant inheritance disorder with a 1/5000-live-birth prevalence. More than 3000 mutations have been characterized thus far in the FBN1 gene. The goal of this study is to facilitate Marfan syndrome diagnosis in Jordanian patients using a molecular genetic testing. All of the 65 coding exons and flanking intronic sequences of the FBN1 gene were amplified using polymerase chain reaction and were subjected to sequencing in five unrelated Jordanian patients suspected of having Marfan syndrome. Four different mutations were identified, including two novel mutations: the c.1553dupG frame-shift (p.Tyr519Ilefs*14) and the c.6650G>A (p.Cys2217Tyr) missense mutations. Two other missense mutations, c.2243G>A (p.Cys748Tyr) and c.2432G>A (p.Cys811Tyr), have been previously detected. Patient number five was heterozygous for the synonymous substitution variant c.1875T>C (p.Asn625Asn; rs#25458). Additionally, eight variants in the intronic sequence of the FBN1 gene were identified, of which the c.2168-46A>G mutation was a new variant. The data provide molecular-based evidence linking Marfan syndrome to pathogenic mutations in the FBN1 gene among Jordanians for the first time. Thus, our results will contribute to the better management of the disease using molecular tools and will help in genetic counseling of the patients' families.