Table 1.

Clinical findings in individuals with heterozygous de novo HDAC3 variants

Proband	Individual 1	Individual 2	Individual 3	Individual 4	Individual 5	Individual 6
mRNA (GenBank: NM_003883.4)	c.328G>A	c.1075C>T	c.277G>A	c.797T>C	c.799G>A	c.601C>T
Protein (GenBank: NP_003874.2)	p.Ala110Thr	p.Arg359Cys	p.Asp93Asn	p.Leu266Ser	p.Gly267Ser	p.Pro201Ser
Ancestry	Asian	Asian	European	European	European	European
Sex	female	female	male	female	male	male
Age at last evaluation	25 years	5 years	6 years	12 years	15 years	12 years
Gestational age at delivery	full-term, cesarean delivery	36 weeks, vaginal delivery	40 weeks, vaginal delivery	not available	35 weeks, vaginal delivery (dizygotic twin)	full-term, vaginal delivery
Birth weight	1.98 kg	2.10 kg	3.30 kg	not available	2.04 kg	4.17 kg
Intellectual disability	severe	severe	moderate	mild	moderate	no
Neurodevelopmental delay	yes	yes	yes	yes	yes	no
Musculoskeletal abnormalities	scoliosis, varus of the proximal tibia, hand joint deformity	polydactyly, syndactyly	no	joint hypermobility	hand joint deformity	neonatal torticollis
Seizure	yes	no	yes	no	no	yes
Facial dysmorphism	yes	yes	no	no	yes	no
Brain MRI findings	no specific findings	no specific findings	subcortical heterotopia	focus of nodular heterotopia	mildly dilated vestibular ducts	no specific findings
Genitourinary anomaly	no	congenital hydronephrosis	phimosis	no	congenital unilateral right hydronephrosis with vesicoureteral reflux	no
Microcephaly	yes	yes	no	no	no	no
Hearing impairment	sensorineural type	no	no	no	mixed type	no
Failure to thrive	yes	yes	no	no	no	no
Congenital heart disease	yes	yes	no	no	no	no
Autistic behavior	yes	no	yes	no	no	no
Other findings	microtia	–	–	subcutaneous scalp arteriovenous malformation	type 1 diabetes, chronic acral warts	–