Table 1.

Clinical Characteristics of Affected Individuals with DHX30 Alterations

Clinical findings	Proband A	Proband B	Proband C	Proband D	Proband E	Proband F	Proband G	Proband H	Proband I	Proband J	Proband K	Proband L
Sex	Female	Male	Female	Female	Male	Female	Female	Female	Female	Male	Female	Male
Age at last examination (years)	3 9/12	13	6 3/12	8	17	14	14 2/12	8	6 1/12	4 8/12	6 5/12	4 8/12
Intellectual disability	+	+	+	+	+	+	+	+	+	+	+	+
Age of first words (years)	1 8/12	4	–	–	–	–	–	–	–	–	–	–
Speech ability	20 words	4 words	non-verbal	non-verbal	non-verbal	non-verbal	non-verbal	non-verbal	non-verbal	non-verbal	non-verbal	non-verbal
Motor development delay	+	+	+	+	+	+	+	+	+	+	+	+
Muscular hypotonia	+	+	+	+	+	+	+	+	+	+	+	+
Age of walking (years)	2 8/12	6	–	–	6	–	3	–	–	–	5	8
Gait abnormalities	ataxic	ataxic	no independent walking	no independent walking	ataxic; only short distances independent	no independent walking	ataxic	no independent walking	no independent walking	no independent walking	ataxic	ataxic
Autistic features	+	–	+	–	+	+	+	–	+	–	+	–
Sleep disturbance	+	+	+	+	–	–	+	+	+	–	–	–
Seizures	+	–	–	+	–	–	–	–	+	–	–	–
Feeding difficulties	+	+	–	–	+	+	+	+	+	+	–	+
Strabismus	+	–	+	–	–	–	–	–	+	+	+	+
Joint hypermobility	+	–	+	–	+	+	–	–	+	–	+	–
Cerebral MRI anomalies	–	–	–	delayed myelination, cerebellar atrophy, enlarged ventricles	cortical atrophy, dilated ventricles	mild cerebral atrophy	delayed myelination	cerebral atrophy, delayed myelination, dilated ventricles	cerebral atrophy	delayed myelination, dilated ventricles, corpus callosal abnormalities	delayed myelination, cerebellar atrophy, dilated ventricles	delayed myelination, cerebellar atrophy, dilated ventricles
DHX30 alteration	c.1478G>A p.Arg493His	c.1478G>A p.Arg493His	c.1685A>G p.His562Arg	c.2342G>A p.Gly781Asp	c.2342G>A p.Gly781Asp	c.2344C>T p.Arg782Trp	c.2344C>T p.Arg782Trp	c.2344C>T p.Arg782Trp	c.2353C>T p.Arg785Cys	c.2353C>T p.Arg785Cys	c.2353C>T p.Arg785Cys	c.2354G>A p.Arg785His

+, present; –, absent;