SNP Shot: Genomic Insights

Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES) is a disorder primarily affecting eyelid development. Individuals with BPES characteristically exhibit a narrowed eye opening (blepharophimosis), drooping eyelids (ptosis), and an epicanthus inversus, which is an upward-slanting skin fold of the lower eyelid near the inner corner of the eye. Furthermore, they often have an increased distance between the inner eye corners (telecanthus). These eyelid irregularities can restrict the ability to fully open the eyes, potentially impairing vision.

Beyond the eyelids, other facial and ocular structures may be mildly affected in BPES. Individuals are more prone to developing vision impairments like nearsightedness (myopia) or farsightedness (hyperopia) during childhood. Eye misalignment (strabismus) or amblyopia, commonly known as "lazy eye," affecting one or both eyes, may also occur. Characteristic facial features sometimes present in BPES patients include a wide nasal bridge, low-positioned ears, and a short philtrum, which is a reduced distance between the nose and upper lip.

BPES presents in two subtypes, differentiated by their specific symptoms. Both type I and type II share the common eyelid malformations and other facial characteristics. However, type I is uniquely linked to primary ovarian insufficiency in women, leading to irregular and eventual cessation of menstruation before the age of 40. Primary ovarian insufficiency may result in reduced fertility (subfertility) or complete infertility.

Inheritance:

BPES typically follows an autosomal dominant inheritance pattern. This implies that only one copy of the mutated gene in each cell is enough to cause the condition. In certain instances, an affected person inherits the mutated gene from a parent who also has BPES. In other cases, the condition arises from new gene mutations and occurs in individuals with no prior family history of BPES.