Acquired microcephaly in blepharophimosis-ptosis-epicanthus inversus syndrome because of an interstitial 3q22.3q23 deletion

The Genetic and Clinical Features of FOXL2-Related Blepharophimosis, Ptosis and Epicanthus Inversus Syndrome

Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES) is a craniofacial disorder caused by heterozygous variants of the forkhead box L2 (FOXL2) gene. It shows autosomal dominant inheritance but can also occur sporadically. Depending on the mutation, two phenotypic subtypes have been described, both involving the same craniofacial features: type I, which is associated with premature ovarian failure (POF), and type II, which has no systemic features. The genotype-phenotype correlation is not fully understood, but it has been hypothesised that type I BPES involves more severe loss of function variants spanning the whole gene. Type II BPES has been linked to frameshift mutations that result in elongation of the protein rather than complete loss of function. A mutational hotspot has been identified within the poly-alanine domain, although the exact function of this region is still unknown. However, the BPES subtype cannot be determined genetically, necessitating informed genetic counselling and careful discussion of family planning advice in view of the associated POF particularly as the patient may still be a child. Following puberty, female patients should be referred for ovarian reserve and response assessment. Oculofacial features can be managed with surgical intervention and regular monitoring to prevent amblyopia.

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

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.

Kaufman oculocerebrofacial syndrome: Novel UBE3B mutations and clinical features in four unrelated patients

The "blepharophimosis-mental retardation" syndromes (BMRS) consist of a group of clinically and genetically heterogeneous congenital malformation syndromes, where short palpebral fissures and intellectual disability associate with a distinct set of other morphological features. Kaufman oculocerebrofacial syndrome represents a rare and recently reevaluated entity within the BMR syndromes and is caused by biallelic mutations of UBE3B. Affected individuals typically show microcephaly, impaired somatic growth, gastrointestinal and genitourinary problems, ectodermal anomalies and a characteristic face with short, upslanted palpebral fissures, depressed nasal bridge. and anteverted nares. Here we present four patients with five novel UBE3B mutations and propose the inclusion of clinical features to the characteristics of Kaufman oculocerebrofacial syndrome, including prominence of the cheeks and limb anomalies.