Table 2.

Frequency of major clinical features in patients with recessive KIF7 or C5orf42 variants from the literature and this study

Clinical feature	KIF7-positive ACLS/ JBTS	C5orf42-positive JBTS/ OFDVI
(Relative) Macrocephaly	28/34 (82%)	5/5 (100%)
Prominent/broad forehead	34/38 (89%)	9/9 (100%)
Hypertelorism	34/37 (92%)	7/8 (88%)
Depressed/wide nasal bridge	33/34 (97%)	6/6 (100%)
Polydactyly	26/41 (63%)	37/71 (52%)
Abnormal corpus callosum	38/40 (95%)	6/13 (46%)
MTS/VH	18/32 (56%)	77/77 (100%)
Developmental delay/ID	40/41 (98%)	36/36 (100%)
Seizure	7/18 (39%)	2/19 (11%)
Ocular motor apraxia	0/9 (0%)	27/38 (71%)
Nystagmus/strabismus	9/18 (50%)	13/21 (62%)
JBTS breathing abnormalities	1/10 (10%)	14/28 (50%)

ACLS acrocallosal syndrome, JBTS Joubert syndrome, OFDVI oral-facial-digital syndrome type VI

MTS molar tooth sign, VH vermis hypoplasia, ID intellectual disability