Pathogenic variants in this gene are associated with defects in the connective tissue. The clinical presentation may have variable severity ranging from mild forms to, in a few cases, perinatal death (Mihalic Mosher et al., Eur J Hum Genet 2019).
The main features related to variants in the B4GALT7 gene are:
• Short stature*
• Muscle hypotonia (from severe congenital to mild)*
• Bowing of limbs*
• Joint hypermobility, especially of the hands
• Radioulnar synostosis
• Skin hyperextensibility and soft, doughy skin**
• Delayed wound healing
Recognizable facial dysmorphisms:
• Short face
• Midface hypoplasia (often giving an appearance of prominent forehead)
• Narrow mouth
• Proptosis
• Loose skin
Other clinical features, distinctive but not always present:
• Developmental delay, motor** and/or cognitive (mild to severe)**
• Ophthalmological abnormalities (strabismus, hypermetropia, myopia, blue sclerae, glaucoma, megalocornea, clouded cornea, iris and optic nerve coloboma, cataract)
• Osteopenia**
• Pes planus**
• Bilateral elbow contractures or limited elbow movement
• Scoliosis
• Sparse scalp hair
Other less frequent clinical features:
• Cleft palate
• Dental anomalies
• Cardiovascular abnormalities
• Hearing loss (sensorineural or conductive)
• Ulnar deviation of fingers
• Pectus carinatum
• Hip dysplasia
• Cryptorchidism
• Vesicoureteral reflux
Stars indicate major (*) and minor (**) diagnostic criteria according to the 2017 International Classification of the Ehlers-Danlos syndromes (Malfait et al., Am J Med Genet C 2017).
B4GALT7