Table 1.
Key Neurobehavioral Features Found in SMS and PTLS Patients
| Neurobehavioral features | SMS | PTLS | ||
|---|---|---|---|---|
| % in common deletion | % in RAI1 mutations | % in common duplication | % in small duplications | |
| Variable mental retardation or cognitive impairment | 100 | 100 | 100 | 100 |
| Motor and speech delay | >90 | 70 | 100 | 100 |
| Sleep disturbance | 90 | 100 | 66.6 | 75 |
| Infantile hypotonia | >90 | 61 | 88.8 | 75 |
| Overt seizures | 11–30 | 16.6 | NR | NR |
| EEG abnormalities | 49 | NR | 66.6-70 | 5.8 |
| Attention seeking | 80–100 | 100 | NR | NR |
| Onychotillomania | 25–85 | 100 | NR | NR |
| Polyembolokoilamania | 25–85 | 80 | NR | NR |
| Hand biting/self-biting | 80 | 60 | NR | NR |
| Self-injurious behaviors | 70–90 | 100 | NR | NR |
| Self-hugging/hand wringing | 50–80 | 100 | NR | NR |
| Head banging/face slapping | 70 | 90 | NR | NR |
| Self-picking | 54 | 100 | NR | NR |
| Hyperactive | 80 | 100 | >70 | 66.6 |
| Autistic features | NR | NR | 87.5 | 66.6 |
A comparison between the phenotypes present in patients with the genomic rearrangements and point mutations of RAI1 gene is shown. For SMS, the clinical features are presented in the percentage of patients carrying either the common 17p11.2 deletion (~3.7 Mb) or a mutation in RAI1 gene. The percentages of features in PTLS are represented for patients that harbor the common 17p11.2 duplication (~3.7 Mb) or small duplications (<1 Mb). (NR: not reported) [25, 27-29].