Table 1

Summary of molecular and clinical data in 14 individuals with mutations in FOXP2

	Family 1		Family 2		Family 3		Family 4	Family 5	Family 6	Family 7			Family 8
Mutation in FOXP2	Deletion exons 12-17		p.(Arg353*)		p.(Arg561Pro)		p.(Arg503*)	p.(Arg589*)	p.(Phe563Leufs*28)	p.(Arg503*)			p.(Pro530Leu)
Detected in the index by	SNP Array		Sanger		Sanger		NGS panel	Trio exome	Trio exome	NGS panel			Sanger
	Index 1	Index 2	Index	Mother	Index	Father	Index	Index	Index	Index	Sister	Father	Index	Father
Age at last investigation	11 years	11 years	14 years	35 years	10 years 10 months	nd	6 years	9 years 11 months	19 years	6.5 years	4.5 years	36 years	6.5 years	40 years
Delayed speech	+	+	+	nd	+	+	+	+	+	+	+	+	+, 2.5 years	+
Age of first words	4 years	4 years	4 years	nd	5 years	nd	13 months	4.5 years	7 years	4 years	8 months	7 years	13 months	nd
Current speech abilities	Short sentences	Short sentences	Sentences	Sentences	Significantly impaired	nd	Sentences	Only two words, unusual vocalisations	Not fluent	Five words	Three-word sentences	Simple sentences	Good vocabulary, incomplete phrases	Still speech therapy
Dyspraxia	−	−	+	+	nd	nd	nd	na	−	nd	nd	−	nd	nd
Stuttering	−	−	−	+	nd	nd	nd	na	+	nd	nd	−	nd	nd
Slurred articulation	+	+	+	+	nd	nd	nd	na	+	nd	nd	+	+	nd
Communication aids required	−	−	−	−	+	−	−	+	−	−	−	−	+	−
Verbal comprehension (formally tested)	Impaired	Impaired	Impaired	nd	nd	nd	Limited auditive memory	Impaired	Good (no test)	nd	nd	nd	Impaired	nd
Walking age	18 months	18 months	14 months	nd	20 months	nd	16 months	15 months	15 months	14 months	18 months	nd	13 months	Normal
Latest IQ (formally tested)	78	79	72	nd	70	nd	Average	nd	nd	nd	nd	nd	72	Average
Learning difficulties/educational support/special school	+	+	+	+	+	nd	+	+	+	+	+	+	+	+
Behavioural anomalies	−	−	−	−	Autistic features	nd	−	ASD	ASD	Hyperactivity, temper tantrums	−	−	−	−

ASD, autism spectrum disorder (formally tested); na, not applicable; nd, no data or not determined; NGS, next generation sequencing; Sanger, targeted sequencing.