Differential Diagnosis: Flat Nasal Bridge, Mongoloid Slant, Epicanthus Inversus with Normal Growth and Development
The most likely diagnosis is Blepharophimosis-Ptosis-Epicanthus Inversus Syndrome (BPES) Type II, given the specific combination of epicanthus inversus with normal growth and development. 1, 2
Primary Diagnostic Consideration
Blepharophimosis-Ptosis-Epicanthus Inversus Syndrome (BPES)
BPES is the only condition that characteristically presents with epicanthus inversus (a vertical skin fold arising from the lower eyelid that inserts medially in the upper lid) as a defining feature. 2 The syndrome has four cardinal features:
- Shortened horizontal palpebral fissures (blepharophimosis)
- Severe ptosis with poor levator function
- Epicanthus inversus (the key distinguishing feature)
- Telecanthus (increased inner canthal distance with normal outer canthal distance)
Type II BPES specifically presents with only craniofacial features and no systemic involvement, which aligns with the normal growth and development described in your case. 1 This is caused by frameshift mutations in the FOXL2 gene that result in protein elongation rather than complete loss of function. 1
Important Differential Diagnoses to Exclude
Down Syndrome (Trisomy 21)
While Down syndrome commonly presents with:
- Upslanting palpebral fissures
- Epicanthal folds (standard epicanthus, not inversus)
- Flat nasal bridge
- Hypotonia
- Protruding tongue
Critical distinguishing features: Down syndrome presents with epicanthal folds (standard type), not epicanthus inversus. 3, 4, 5 Additionally, Down syndrome typically involves developmental delays, hypotonia, and intellectual disability—not normal growth and development. 5, 6
Fetal Alcohol Spectrum Disorder (FASD)
FASD presents with:
- Small palpebral fissures
- Smooth philtrum
- Thin vermillion border
- Growth deficiency (≤10th percentile for height/weight)
- CNS abnormalities (structural, neurologic, or functional)
Key exclusion criteria: FASD requires both growth deficiency and CNS abnormalities for diagnosis. 7, 8 The presence of normal growth and development effectively rules out FASD.
Other RASopathies (Cardio-Facio-Cutaneous Syndrome, Noonan Syndrome, Costello Syndrome)
These syndromes share overlapping features including:
- Hypertelorism
- Downslanting palpebral fissures
- Epicanthal folds
- Short stature
- Cardiac abnormalities
Distinguishing features: None of these syndromes present with epicanthus inversus as a characteristic feature. 9 CFC syndrome specifically presents with coarse facial features, sparse curly hair, and typically involves cognitive delay—inconsistent with normal development. 9
Clinical Approach
Immediate steps:
- Examine for the four cardinal BPES features systematically: measure palpebral fissure length, assess levator function, confirm epicanthus inversus direction (lower to upper lid), and measure intercanthal distances
- Document growth parameters objectively using standardized growth charts to confirm normal development
- Assess developmental milestones to verify truly normal neurodevelopment
- Obtain detailed family history for autosomal dominant inheritance pattern (though 50% are sporadic cases) 2
Genetic confirmation:
- Refer for FOXL2 gene testing to confirm BPES diagnosis 1, 2
- Genetic counseling is essential, particularly for female patients, as Type I BPES (cannot be distinguished genetically from Type II initially) involves premature ovarian failure 1
Critical pitfall: Do not assume Type II BPES based solely on current normal development in young children. Female patients require post-pubertal ovarian reserve assessment to definitively distinguish Type I from Type II. 1
Ophthalmologic management:
- Refer to pediatric ophthalmology for amblyopia prevention through regular monitoring
- Surgical intervention planning for ptosis correction (typically staged procedures)
- Monitor for associated strabismus 1
The combination of epicanthus inversus (not standard epicanthal folds) with normal growth and development is pathognomonic for BPES Type II, making this the primary diagnosis to pursue with genetic confirmation.