Table 1. Clinical findings in four affected males.

Individual	IV-1	IV-4	III-3a,b	II-1a
Age (years)	5 ½	11 ½	45	71
Intellectual disability	Mild to moderate Functional level was 1 ½ years at age 4 ½ years	Mild Doesn't read	Mild. Moving to sheltered living. Reads and drives a car	Moderate/severe Cannot read/write
Education and work	Not relevant	Attends school for children with special needs	Attended school for children with special needs. Works in a sheltered environment	Has lived in an institution since age 13 years
Measurements at birth	At 41 ½ weeks: weight 4895 g, length 52 cm, OFCd 37 cm	At 37 weeksc: weight 2600 ge, length 50 cm, OFCd not recorded	At 32 weeks: weight 2100 g	NA
Infancy	Content baby	Cried a lot. Slept poorly	NA	NA
Feeding difficulties	Gastrostomy (10 months to 3 years). Picky eater. Difficulty in chewing and swallowing.	Severe feeding problems until age 1 year. Picky eater. Difficulty in chewing.	Very selective food preferences when younger	NA
Walked	22 months	18 months	15 months	NA
Speech	Age 3 years: many signs, no words Age 5 ½ years: short sentences	Age 3 years: a few words	Most delayed area of development	NA
Social adjustment and behavior	Difficulty in communicating with and understanding other children	Plays with other children. Dislikes noise and commotion	Adjusts slowly to new activities	NA
Autism	Autism	Autism spectrum disorder	Autism spectrum disorder likely	Behavioral issues in childhood
Dysmorphic features	Broad forehead, fine hair with receding hairline bitemporally, hypertelorism, widely-spaced teeth, concave nails	Broad forehead, fine hair with receding hairline bitemporally, hypertelorism, broad nasal bridge, pale blue irides	High broad forehead Receding hairline Large beaked noseb	NA
Motor function	Poor fine+gross motor coordination. Reduced balance, strength and endurance	Delayed gross motor development	Poor gross motor coordination	Poor gross motor coordination
Stiff gait	Yes	Yes	Yes	NA
Growth	Height 10–25th centile Weight for height 2.5–10th centile OFCd 2.5th centile	Height 50th centile Thin OFCd 25th – 50th centile	Average height Truncal obesity Normocephalic	NA
Cranial MRI	At 12 months: non-specific white matter changes	At 3 years: normal	Not performed	Not performed
Normal genetic investigations	FGD1 (MLPA and sequencing), MECP2 (MLPA), MID1 (sequencing), CNV screening (180-k oligo array CGH)	Sequencing: MID1, CUL4B, SHANK3, FLNA, FGD1, CNV screening (105 -k oligo array CGH)	Not known	Not known

Abbreviation: NA, not available.

^aLimited information available for this individual.

^bAs a child he resembled IV-4 in terms of facial appearance and personality.

^cCesarean section for fetal distress.

^dOccipito-frontal head circumference.

^eHis dizygous twin had a birthweight of 2700 g and a length of 50 cm.