Baraitser-Winter syndrome type 1 in an infant with craniofacial dysmorphism, facial asymmetry, and sensorineural hearing loss

We report a 10-month-old female presenting with motor developmental delay, generalized hypotonia, and moderate bilateral sensorineural hearing impairment. Clinical evaluation revealed craniofacial dysmorphism including macrocephaly, facial asymmetry, broad forehead, hypertelorism, wide nasal bridge, flattened nasal dorsum, thin upper lip vermilion with a prominent cutaneous segment, flattened philtrum, and wide mouth. Additional findings included tapered fingers with a characteristic “hockey-stick” palmar crease, short toes, body asymmetry, and failure to thrive during early infancy. Differential diagnoses initially considered included Robinow syndrome and frontonasal dysplasia.
Whole-exome sequencing performed as a trio identified a heterozygous pathogenic de novo variant in ACTB [NM_001101.5:c.901G>A p.(Gly301Ser)], consistent with Baraitser-Winter syndrome type 1 (BRWS1) [MIM:243310]. The patient’s phenotype largely aligns with the documented clinical spectrum of BRWS1, which is highly variable. Features such as sensorineural hearing loss and facial asymmetry, although less frequently reported, fall within the documented range of this disorder.
This case emphasizes the variability of BRWS1 and highlights the importance of comprehensive genetic testing for accurate diagnosis and counseling.