Case 5 is a 34-year-old man, the third child of healthy non-consanguineous parents (patient 16 from the study of De Rocker et al). He was born at term. Birth weight was 3750 g (75th). He had intellectual disability, speech delay and epilepsy. On examination at age 34 years, height was 150 cm (3rd centile) and head circumference 53 cm (3rd centile, corrected for height). He had facial dysmorphism: microretrognathia, short philtrum and mild trigonocephaly. Scoliosis and cryptorchidism were also noted. CGH was reported as arr 2p25(2231163–8300707)(hg 19)x1 with deletion of the SOX11 and MYT1L genes. This was paternally inherited; a detailed phenotypic description of the father was not available, but he was reported to be epileptic and had intellectual disability and speech delay.
Case 7 is a 2-year-old girl, the first child of healthy non-consanguineous parents. She was born at 39 weeks of gestation by elective caesarean section. Birth weight was 3.5 kg (50th). There were feeding difficulties and poor weight gain in the first month of life. This resulted in hospital admission. Gastro-oesophageal reflux was diagnosed and the feeding difficulties resolved with gaviscon. At this time generalised hypotonia was noted. There was a history of mild gross motor delay; she first sat independently at 10 months and walked at 15 months. At the age of 2 years, she had begun to run. There were no concerns relating to fine motor skills. There was mild speech delay; at the age of 2 years, she was not producing two word phrases. She was physically well. On examination her head circumference was 47 cm (50th centile) and weight 10 kg (2nd centile). She had deep set eyes, full cheeks and thick lips. There was sparse scalp hair. She had bilateral fifth finger clinodactyly and hypoplasia of the nails of the fifth fingers and toes. CGH was reported as arr2p25.2(5166592–6400126)(hg19)x1. Only the SOX11 gene was deleted, and it was not possible to test parental samples.