PMM2 and hearing loss disorder: Specifically, biallelic mutations were detected (i) in the PIGG gene in an 11-year-old male with ASD Asperger-type; (ii) in the PMM2 gene in a 14-year-old female with ASD, hearing loss, and ptosis; and (iii) in the CEP290 gene in a 13-year-old male with ID and attention deficit (Table 4).