LAUSR

To the Editor, The ultrarare clinical association of Duane retraction syndrome (DRS) with or without deafness and inner ear defects, has been recently related with deleterious variants in MAFB (MIM*608968) and found in few sporadic pedigrees (Figure 1A). We describe an Italian family with a novel MAFB variant, in which the index-case, a 10-year-old female, underwent genetic evaluation for neurodevelopmental delay, autism spectrum disorder (ASD), DRS type 1, and inner ear agenesis with profound bilateral deafness. She was the only child of unrelated parents, born at 40 gestational weeks, after a normal pregnancy by caesarian section. Birth parameters were weight 3000 g (10–25 centile), height 46.5 cm (10 centile), occipitofrontal circumference (OFC) 34 cm (50 centile) and Apgar score 9 0 /10 0 . She sat at 12 months and walked without support at 24 months. A computerized tomography (CT) exam of the mastoid (15 months) documented left cochlea absence with malformed semicircular canals and saccule, and right cochlear-vestibular aplasia. Both inner ear canals were malformed as well as cochlear nerves bilaterally absent, requiring surgical implantation of inner ears prosthesis at the encephalic trunk (12 months). Moderate intellectual disability (ID) (IQ = 73, Leiter-R scale) and ASD (ADOS-2 = 16) were diagnosed (5 years). The family described behavioral disturbances, including motor stereotypies and self-harm injures episodes, treated with psychomotor rehabilitation. At genetic evaluation (10 years), the height was 128 cm (3–10 centile), weight 32 kg (25–50 centile), and OFC 52.5 cm (25–50 centile). She showed mild facial and extremities anomalies (Figure 1B). Language was absent, she had a limited vocabulary and communicated mainly using gestures. The father only displayed DRS type 1. The trio-based whole-exome sequencing (WES, Twist Bioscience; NovaSeq6000 platform, Illumina) identified in the child and her father