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

ABSTRACT: 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.

SUBMITTER: Rosenfeld JA

PROVIDER: S-EPMC3125720 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ObjectiveChromosomal 1q21.1 deletions and duplications are genomic disorders that are usually diagnosed postnatally. However, the genotype-phenotype correlations of 1q21.1 copy number variants (CNVs) during the prenatal period are still not clear. This study aimed to provide a systematic summary of prenatal phenotypes for such genomic disorders.MethodsIn total, 26 prenatal amniotic fluid samples diagnosed with 1q21.1 microdeletions/microduplications were obtained from pregnant women who opted for invasive prenatal testing. Karyotypic analysis and chromosomal microarray analysis (CMA) were performed for all cases simultaneously. The pregnancy outcomes and health conditions after birth in all cases were followed up. Meanwhile, prenatal cases with 1q21.1 microdeletions or microduplications in the literature were retrospectively collected.ResultsIn total, 11 pregnancies (11/8,252, 0.13%) with 1q21.1 microdeletions and 15 (15/8,252, 0.18%) with 1q21.1 microduplications were identified. Among these 1q21.1 CNVs, 4 cases covered the thrombocytopenia-absent radius (TAR) region, 16 cases covered the 1q21.1 recurrent microdeletion/microduplication region, and 6 cases covered all regions mentioned above. The prenatal abnormal ultrasound findings were recorded in four participants with 1q21.1 deletions and seven participants with 1q21.1 duplications. Finally, three cases with 1q21.1 deletions and five with 1q21.1 duplications terminated their pregnancies.ConclusionIn the prenatal setting, 1q21.1 microdeletions were associated with increased nuchal translucency (NT), anomalies of the urinary system, and cardiovascular abnormalities, while 1q21.1 microduplications were correlated with cardiovascular malformations, nasal bone dysplasia, and increased NT. In addition, cerebral ventriculomegaly might be correlated with 1q21.1 microduplications. Considering the variable expressivity and incomplete penetrance of 1q21.1 CNVs, long-term follow-up after birth should be carried out in these cases.

Project description:Objective: Chromosomal 1q21.1 deletions and duplications are genomic disorders which are usually diagnosed postnatally. However, the genotype-phenotype correlations of 1q21.1 copy number variants (CNVs) during prenatal period are still not clear. This study aimed to provide a systematical summary of prenatal phenotypes for such genomic disorders. Methods: Twenty-six prenatal amniotic fluid samples diagnosed with 1q21.1 microdeletions/microduplications were obtained from pregnant women who opted for invasive prenatal testing. Karyotypic analysis and chromosomal microarray analysis (CMA) were performed for all cases simultaneously. The pregnancy outcomes and health conditions after birth for all cases were followed up. Meanwhile, prenatal cases with 1q21.1 microdeletions or microduplications in the literature were retrospectively collected. Results: Eleven pregnancies (11/8252, 0.13%) with 1q21.1 microdeletions and fifteen (15/8252, 0.18%) with 1q21.1 microduplications were identified. Among these 1q21.1 CNVs, four cases covered thrombocytopenia-absent radius (TAR) region, sixteen cases covered 1q21.1 recurrent microdeletion/microduplication region, and six cases covered all regions mentioned above. The prenatal abnormal ultrasound findings were recorded in four participants with 1q21.1 deletions and seven participants with 1q21.1 duplications. Finally, three cases with 1q21.1 deletions and five with 1q21.1 duplications terminated their pregnancies. Conclusion: 1q21.1 microdeletions were associated with increased nuchal translucency (NT), anomalies of urinary system and cardiovascular abnormalities, and 1q21.1 microduplications were correlated with cardiovascular malformations, nasal bone dysplasia and increased NT in prenatal setting. In addition, cerebral ventriculomegaly might be correlated with 1q21.1 microduplications. Considering the variable expressivity and incomplete penetrance of 1q21.1 CNVs, long term follow up after birth should be carried out for these cases. We identified 26 fetuses carrying the 1q21.1 microdeletions and microduplications using chromosomal microarray analysis. And diverse prenatal phenotypes and the critical genes involved in the deleted/duplicated regions were described in this study.

Project description:Deletion and the reciprocal duplication in 16p11.2 were recently associated with autism and developmental delay.We indentified 27 deletions and 18 duplications of 16p11.2 were identified in 0.6% of all samples submitted for clinical array-CGH (comparative genomic hybridisation) analysis. Detailed molecular and phenotypic characterisations were performed on 17 deletion subjects and ten subjects with the duplication.The most common clinical manifestations in 17 deletion and 10 duplication subjects were speech/language delay and cognitive impairment. Other phenotypes in the deletion patients included motor delay (50%), seizures ( approximately 40%), behavioural problems ( approximately 40%), congenital anomalies ( approximately 30%), and autism ( approximately 20%). The phenotypes among duplication patients included motor delay (6/10), behavioural problems (especially attention deficit hyperactivity disorder (ADHD)) (6/10), congenital anomalies (5/10), and seizures (3/10). Patients with the 16p11.2 deletion had statistically significant macrocephaly (p<0.0017) and 6 of the 10 patients with the duplication had microcephaly. One subject with the deletion was asymptomatic and another with the duplication had a normal cognitive and behavioural phenotype. Genomic analyses revealed additional complexity to the 16p11.2 region with mechanistic implications. The chromosomal rearrangement was de novo in all but 2 of the 10 deletion cases in which parental studies were available. Additionally, 2 de novo cases were apparently mosaic for the deletion in the analysed blood sample. Three de novo and 2 inherited cases were observed in the 5 of 10 duplication patients where data were available.Recurrent reciprocal 16p11.2 deletion and duplication are characterised by a spectrum of primarily neurocognitive phenotypes that are subject to incomplete penetrance and variable expressivity. The autism and macrocephaly observed with deletion and ADHD and microcephaly seen in duplication patients support a diametric model of autism spectrum and psychotic spectrum behavioural phenotypes in genomic sister disorders.

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

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