Barber-Say syndrome (BBRSAY) is a rare congenital condition characterized by severe hypertrichosis, especially of the back, skin abnormalities such as hyperlaxity and redundancy, and facial dysmorphism, including macrostomia, eyelid deformities, ocular telecanthus, abnormal and low-set ears, bulbous nasal tip with hypoplastic alae nasi, and low frontal hairline (summary by Roche et al., 2010).

Wiedemann-Steiner syndrome (WSS) is characterized by developmental delay, intellectual disability, and characteristic facial features, with or without additional congenital anomalies. The facial features include thick eyebrows with lateral flare, vertically narrow and downslanted palpebral fissures, widely spaced eyes, long eyelashes, wide nasal bridge, broad nasal tip, thin vermilion of the upper lip, and thick scalp hair. About 60% of affected individuals have hypertrichosis cubiti ("hairy elbows"), which was once thought to be pathognomic for the syndrome, with a majority having hypertrichosis of other body parts. Other clinical features include feeding difficulties, prenatal and postnatal growth restriction, epilepsy, ophthalmologic anomalies, congenital heart defects, hand anomalies (such as brachydactyly and clinodactyly), hypotonia, vertebral anomalies (especially fusion anomalies of the cervical spine), renal and uterine anomalies, immune dysfunction, brain malformations, and dental anomalies.

FOXP1 syndrome is characterized by delays in early motor and language milestones, mild-to-severe intellectual deficits, speech and language impairment in all individuals regardless of level of cognitive abilities, and behavior abnormalities (including autism spectrum disorder or autistic features, attention-deficit/hyperactivity disorder, anxiety, repetitive behaviors, sleep disturbances, and sensory symptoms). Other common findings are oromotor dysfunction (contributing to speech and feeding difficulties), refractive errors, strabismus, cardiac abnormalities, renal abnormalities, cryptorchidism, hypertonia, hearing loss, and epilepsy. To date, more than 200 individuals have been identified with FOXP1 syndrome.