Molecular Genetic Analysis of FOXL2 Gene in Two Iranian Families with Blepharophimosis-Ptosis-Epicanthus Inversus Syndrome

Abstract

Background: Blepharophimosis-ptosis-epicanthus syndrome (BPES) is a rare genetic disorder with autosomal dominant inheritance. There are two distinct phenotypes: BPES type I, which is associated with eyelid abnormalities as well as female infertility or premature menopause due to ovarian resistance to gonadotropins, whereas in type II only eyelid abnormalities are present. Mutations in the forkhead transcription factor 2 (FOXL2) gene are responsible for both types of BPES. Objectives: The purpose of this study was to identify mutations in FOXL2 in two Iranian families (from Tehran) with BPES who were referred to Tehran Medical Genetics laboratory. Methods: The peripheral blood was collected from the affected members of two BPES families and genomic DNA was extracted using salting out method. Then, direct sequencing of whole exon of FOXL2 genewas performed. Results: Two frameshift mutations were identified in FOXL2 gene in two familial cases including NM_023067:c.102_103insA (p.G35Rfs*61)as a novel mutation and NM_023067:c.855_871dup (p.H291Rfs*71) (17-bp insertion). Both mutations cause the protein to be truncated and are responsible for a severe phenotype (BPES type I) which was in harmony with our finding. Conclusions: Our results increased the spectrum of FOXL2 mutations and confirm the mutations associated with BPES type I.