The most striking sign of<unk>  is the co-occurrence of both syndactyly (about 0.03% of births) and long QT syndrome (1% per year) in a single patient. Other common symptoms include cardiac arrhythmia (94%), heart malformations (59%), and autism or an autism spectrum disorder (80% who survive long enough for evaluation). Facial dysmorphologies such as flattened noses also occur in about half of patients. Children with this disorder have small teeth, which due to poor enamel coating, are prone to dental cavities and often require removal. The average age of death due to complications of these symptoms is 2.5 years. Atypical<unk>  has largely the same symptoms as the classical form. Differences in the atypical form are the lack of syndactyly, the presence of musculoskeletal problems (particularly hyperflexible joints), and atrial fibrillation. Patients with atypical<unk>  also have more facial deformities, including protruding foreheads and tongues. Finally, one patient with atypical<unk>  had a body development discrepancy wherein her upper body was normally developed (that of a 6-year-old) while her lower half resembled a 2- or 3-year-old. Children with<unk>  tend to be born via caesarean section due to fetal distress.
Timothy syndrome
Goldenhar syndrome
Joubert syndrome
Wolfram syndrome
Christianson syndrome
Cohen syndrome
Kaufman oculocerebrofacial syndrome
Karak syndrome