see also:
| feature | autism | Asperger's | ADHD | Williams-Beuren syndrome (WBS) |
|---|---|---|---|---|
| impaired social interactions | non-verbal cues, reciprocity, social isolation | awkwardness, odd, non-verbal cues, display of empathy, social isolation | inattention, hyperactivity or impulsivity, may progress to anti-social or conduct disorder PD | often regarded as the opposite of autism; hyperfocus on eyes; highly verbal; overly sociable; “cocktail party”; high empathy; reduced fear of disapproving faces or strangers but increased fear of non-social fears; in adolescence, often experience social isolation, frustration, and loneliness despite their clear desire to connect to other people; anxiety; |
| stereotyped repetitive behavior | simple motor stereotypies, echolalia, repetitive use of objects, or idiosyncratic phrases | pursuit of specific and narrow areas of interest | not significant | no |
| inattention | may not listen | may not listen | easily distracted; careless mistakes; sustained effort tasks problematic; forgetful; | no |
| motor | usually restricted motor skills, often ritualistic | often odd gait, poor coordination | hyperactivity, “on the go”, fidgets | dev. delay in coordination, fine motor skills; often gait issues esp. walking down stairs; hyper-reflexic; nystagmus |
| impulsivity | trouble controlling stereotypic behaviour | trouble controlling stereotypic behaviour | blurts out an answer, difficulty waiting their turn, interrupts | overly sociable, verbally disinhibited |
| speech | usually paucity of speech | odd speech with verbosity, literal interpretations and issues with rhythm, loudness; may use metaphors only they understand | interrupts conversations | rich in emotional descriptors, high in prosody (exaggerated rhythm and emotional intensity), and features unusual terms and strange idioms; often harsh, brassy, or hoarse voice |
| prevalence | 0.15% children? | 0.03% children? | 3-5% children | 0.01% children perhaps much more in milder spectrum without typical facies; |
| genetics | Fragile X syndrome is the most common known single-gene cause of autism | 7q11.23 deletion causes 90-95% of classic cases; WBS locus is prone to recurrent chromosomal rearrangements, including the microdeletion that causes classic WBS. Thought to be due to unequal meiotic recombination, probably mediated by the highly homologous DNA that flanks the commonly deleted region; Haploinsufficiency of the elastin gene is known to lead to the vascular stenoses in WBS and is also thought to predispose to hypertension; Atypical cases with only a subset of the WBS phenotypic spectrum tend to have an inversion of the WBS region; 1) | ||
| associations | autism | ADHD; coeliac disease; early onset type 2 diabetes; hypothyroidism | ||
| other | classic WBS: “elf-like”; short, thin; failure to thrive infants; puffy eye facies; cardiac abn. - SVAS (73%), pulmonary artery stenosis (41%), systemic hypertension (55% adults); pectus excavatum; absolute perfect musical pitch; hyperacusia; impaired spatial processing; dental issues; hallux valgux; many have blue eyes with stellate iris; infantile and adult hypercalcaemia; mild to moderate high-frequency sensorineural hearing loss in adulthood; urinary detrusor overactivity and detrusor-sphincter dyssynergia; IQ usually 60-100 but milder forms may have higher IQ; many sing or play musical instruments with considerable expertise and auditory memory, and rarely forget a name. Usually read and write poorly and struggle with simple arithmetic |