Blepharophimosis, Ptosis, Epicanthus Inversus Syndrome: New Report with a 197-kb Deletion Upstream of FOXL2 and Review of the Literature

Abstract

Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES) is due to heterozygous FOXL2 intragenic mutations in about 70% of the patients, whereas total or partial gene deletions account for a minority of cases. Alteration of FOXL2 regulatory elements has been rarely described in patients with BPES. In this study, a prepubertal girl with BPES due to a 197-kb de novo deletion of the regulatory elements upstream of FOXL2 is reported. This girl presented with additional clinical features such as a soft cleft palate and microcephaly; thus, this copy number variant might have other somatic effects. The present deletion encompasses 2 coding genes (MRPS22 and COPB2), whose homozygous mutations have been associated with microcephaly. In our case, the sequences of the non-deleted allele were normal, ruling out a compound genetic defect. Normal levels of new biomarkers of ovarian reserve (anti-müllerian hormone, inhibin B) likely indicate an early diagnosis of type 2 BPES, but an evolutive gonadal damage will be excluded only by long-term follow-up. Additional reports of microdeletions upstream of FOXL2 are needed to better define the underlying genetic mechanism and the related phenotypic spectrum; the ability of the new hormonal markers to predict ovarian function in adolescence and adulthood should be confirmed.

Keywords: 3q23 deletion; Anti-müllerian hormone; BPES; COPB2; FOXL2; Inhibin B; MRPS22; Ovarian function; Regulatory elements; array CGH.

Fig. 1

Patient with BPES at the age of 3 years and 10 months.

Fig. 2

A Detailed structure of the microdeletion. The genes harbored are indicated by blue boxes; the intervals between the deleted and non-deleted probes of the distal and proximal breakpoints are indicated by striped boxes. Probe and gene positions are referred to GRCh37/hg19. B Schematic representation of microdeletions upstream of FOXL2 in patients with BPES. The numbers 1-9 correspond with those reported in Table 2. The shortest region of deletion overlap (SRO) and FOXL2 are indicated.

Fig. 3

Schematic representation of microdeletions characterized by molecular techniques in patients with BPES and microcephaly. The relative references are reported. Deletion sizes were all converted to GRCh37/hg19.