. Author manuscript; available in PMC: 2009 Oct 3.

Published in final edited form as: Nat Rev Genet. 2008 May;9(5):341–355. doi: 10.1038/nrg2346

Table 1.

ASD-related syndromes

Syndrome	Gene(s) associated with the syndrome	Proportion of patients with the syndrome that have an ASD	Proportion of patients with an ASD that have the syndrome	Refs
15q duplication — Angelman syndrome	UBE3A (and others)	>40%	1–2%	101-103
16p11 deletion	Unknown	High	∼1%	20, 35, 44
22q deletion	SHANK3	High	∼1%	21, 22, 104
Cortical dysplasia-focal epilepsy syndrome	CNTNAP2	∼70%	Rare	37
Fragile X syndrome	FMR1	25% of males; 6% of females	1–2%	105
Joubert syndrome	Several loci	25%	Rare	106
Potocki–Lupski syndrome	Chromosome position 17p11	∼90%	Unknown	107
Smith–Lemli–Optiz syndrome	DHCR7	50%	Rare	108
Rett syndrome	MECP2	All individuals have Rett syndrome	∼0.5%	109
Timothy syndrome	CACNA1C	60–80%	Unknown	24
Tuberous sclerosis	TSC1 and TSC2	20%	∼1%	110

The rates quoted in the table depend on the population that is being evaluated. For example, rates are higher in individuals from simplex families compared with multiplex families, and are higher in dysmorphic and mental retardation populations compared with idiopathic populations. ‘High’ is used for syndromes in which no good estimates exist (that is, only a handful of individuals with the syndrome in question have been identified). It should also be noted that none of the studies cited here indicates that assessment for the autism spectrum disorder (ASD) was performed blind to a patient's primary diagnosis. An expanded version of the table with additional variables can be found in Supplementary information S1 (table). CACNA1C, calcium channel voltage-dependent L type alpha 1C subunit; CNTNAP2, contactin associated protein-like 2; DHCR7, 7-dehydrocholesterol reductase; FMR1, fragile X mental retardation 1; MECP2, methyl CpG binding protein 2; SHANK3, SH3 and multiple ankyrin repeat domains 3; TSC1, tuberous sclerosis 1; TSC2, tuberous sclerosis 2; UBE3A, ubiquitin protein ligase E3A.