Case 6 was a 25-year-old Caucasian male with the full mutation. His developmental milestones were delayed with sitting at 7 months, crawling at 8 months, walking at 1 year, but at 2 years he was only saying single words and he did not speak in sentences until about 4 years of age. His behavior included hand flapping, poor eye contact, tactile defensiveness, hyperactivity, perseveration, tantrum behavior about three to four times a week, mainly with verbal outbursts, yelling and irritability at least once a day. His full scale IQ of 61 fell in a mildly delayed range. On the ADOS Module 4 he met ASD criteria. On the ADIS, he met criteria for social phobia, specific phobia, and generalized anxiety. He also showed some psychotic features with hearing voices, and laughs to himself frequently.
Case 8 was a 22-year-old Caucasian male with a low-level full mutation with methylation mosaicism that was 43% methylated. His developmental milestones were delayed with walking at ~19 months, saying words at 2½ years, but he did not speak in phrases until he was ~3½ years of age. He showed a lot of self-talk, perseverative speech, has difficulty in organizing his thinking, and can be quite tangential. His full scale IQ of 45 fell in a moderately delayed range. On the ADOS, he did not meet full clinical criteria for an ASD, but fell in the PDD-NOS category. On the ADIS he met clinical criteria for Social Phobia.