Table 1.

Clinical features in 25 individuals bearing pathogenic DHX30 variants and frequency of these features in previously reported individuals

DHX30 variant	Heterozygous missense variants within a HCM (this study)	p.(Ala734Asp) mosaic (this study)	Haploinsufficiency/protein truncating variants (this study)	Homozygous p.(Arg725His) (this study)	Heterozygous p.(Arg908Gln) (this study)	Heterozygous missense variants within a HCM (previous studies: Lessel et al. 2017 and Cross et al. 2020)
Sex	11 females/7 males	Female	1 female/3 males	Male	Female	8 females/6 males
Intellectual disability	18/18	+	4/4	?	−	13/13
Speech ability	14/18 non-verbal 4/18 single words	Simple sentences	20 words to normal speech ability	?	Normal speech ability	11/13 non-verbal 2/13 single words
Motor development delay	18/18	+	4/4 mild	+	−	14/14
Muscular hypotonia	17/18	+	3/4	+	−	14/14
Gait abnormalities	10/18 no independent walking 8/18 ataxic	Ataxic gait	0/4 no independent walking 3/4 ataxic gait	?	Ataxic gait	7/13 no independent walking 6/13 ataxic gait
Feeding difficulties	15/18	+	1/4	+	−	11/14
Microcephaly	13/15	+	0/4	−	−	7/10
Joint hypermobility	13/18	+	1/3	−	−	6/14
Brain MRI anomalies	11/17	−	2/3	+	+	10/14
Sleep disturbance	8/18	+	2/3	+	−	7/12
Strabismus	8/18	−	2/4	−	+	6/14
Autistic features	4/14	+	0/3	?	−	7/12
Seizures	3/18	+	2/3	Severe	−	3/14

+, present; −, absent; ?, too young to evaluate; NA, unkown