Speech delays and behavioral problems are the predominant features in individuals with developmental delays and 16p11.2 microdeletions and microduplications

Microdeletions and microduplications encompassing a ~593-kb region of 16p11.2 have been implicated as one of the most common genetic causes of susceptibility to autism/autism spectrum disorder (ASD). We report 45 microdeletions and 32 microduplications of 16p11.2, representing 0.78% of 9,773 individuals referred to our laboratory for microarray-based comparative genomic hybridization (aCGH) testing for neurodevelopmental and congenital anomalies. The microdeletion was de novo in 17 individuals and maternally inherited in five individuals for whom parental testing was available. Detailed histories of 18 individuals with 16p11.2 microdeletions were reviewed; all had developmental delays with below-average intelligence, and a majority had speech or language problems or delays and various behavioral problems. Of the 16 individuals old enough to be evaluated for autism, the speech/behavior profiles of seven did not suggest the need for ASD evaluation. Of the remaining nine individuals who had speech/behavior profiles that aroused clinical suspicion of ASD, five had formal evaluations, and three had PDD-NOS. Of the 19 microduplications with parental testing, five were de novo, nine were maternally inherited, and five were paternally inherited. A majority with the microduplication had delayed development and/or specific deficits in speech or language, though these features were not as consistent as seen with the microdeletions. This study, which is the largest cohort of individuals with 16p11.2 alterations reported to date, suggests that 16p11.2 microdeletions and microduplications are associated with a high frequency of cognitive, developmental, and speech delay and behavior abnormalities. Furthermore, although features associated with these alterations can be found in individuals with ASD, additional factors are likely required to lead to the development of ASD

Severe intellectual disability and autistic features associated with microduplication 2q23.1

We report on two patients with developmental delay, hypotonia, and autistic features associated with duplications of chromosome region 2q23.1-2q23.2 detected by chromosome microarray analysis. The duplications include one OMIM Morbid Map gene, MBD5, as well as seven known RefSeq genes (ACVR2A, ORC4L, EPC2, KIF5C, MIR1978, LYPD6B, and LYPD6). MBD5 lies in the minimum area of overlap of the 2q23.1 microdeletion syndrome. This report provides the first detailed clinical examination of two individuals with a duplication of this region and suggests that brain development and cognitive function may be affected by an increased dosage of the genes involved. © 2012 Macmillan Publishers Limited All rights reserved.link_to_OA_fulltex