[Show abstract][Hide abstract] ABSTRACT: Results of comparative genomic hybridization studies have suggested that rare copy number variations (CNVs) at numerous loci are involved in the cause of mental retardation, autism spectrum disorders, and schizophrenia.
To provide an estimate of the collective frequency of a set of recurrent or overlapping CNVs in 3 different groups of cases compared with healthy control subjects and to assess whether each CNV is present in more than 1 clinical category.
We investigated 28 candidate loci previously identified by comparative genomic hybridization studies for gene dosage alteration in 247 cases with mental retardation, in 260 cases with autism spectrum disorders, in 236 cases with schizophrenia or schizoaffective disorder, and in 236 controls.
Collective and individual frequencies of the analyzed CNVs in cases compared with controls.
Recurrent or overlapping CNVs were found in cases at 39.3% of the selected loci. The collective frequency of CNVs at these loci is significantly increased in cases with autism, in cases with schizophrenia, and in cases with mental retardation compared with controls (P < .001, P = .01, and P = .001, respectively, Fisher exact test). Individual significance (P = .02 without correction for multiple testing) was reached for the association between autism and a 350-kilobase deletion located at 22q11 and spanning the PRODH and DGCR6 genes.
Weakly to moderately recurrent CNVs (transmitted or occurring de novo) seem to be causative or contributory factors for these diseases. Most of these CNVs (which contain genes involved in neurotransmission or in synapse formation and maintenance) are present in the 3 pathologic conditions (schizophrenia, autism, and mental retardation), supporting the existence of shared biologic pathways in these neurodevelopmental disorders.
Archives of general psychiatry 09/2009; 66(9):947-56. DOI:10.1001/archgenpsychiatry.2009.80 · 14.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We describe a 46-month-old child presenting with developmental delay, mild facial dysmorphism, micropenis, strabismus and striking multiple cysts of the corpus callosum who was found to have a de novo interstitial 3.1 Mb 15q24.1q24.2 microdeletion using a 244 K microarray-based comparative genomic hybridization (array-CGH). The cystic lesions were located in the anterior half of the corpus callosum and did not take up gadolinium contrast. There was no other brain abnormality, and the gyral pattern and myelination were normal. There was no history of infectious disease or vascular injury and a metabolic disease was ruled out. Such cystic lesions of the corpus callosum are exceptional in the pediatric literature. Although these brain abnormalities have not been described in other reports with 15q24 microdeletion, we believe that they might be related to the cytogenetic abnormality since the work-up for other causes was negative. We suggest that a chromosomal rearrangement should be ruled out when such corpus callosum lesions are identified.
American Journal of Medical Genetics Part A 07/2009; 149A(7):1504-10. DOI:10.1002/ajmg.a.32904 · 2.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Here we describe the clinical, histopathological and molecular studies of a female proband that died at 2 months of age in the context of a syndromic polymicrogyria. There was no significant family history. Clinical and radiological features included poor contact, cleft palate, facial dysmorphic features with frontal bossing, down-slanting and small palpebral fissures, inferior epicanthic folds, low-set and malformed ears, flat nose, retrognathism and short neck, minor limb anomalies, polymicrogyria that appear more severe in the perisylvian regions and cerebellar vermis hypoplasia. Autopsy findings revealed a patent foramen ovale with persistent left superior vena cava, left renal hypoplasia and microphthalmia. This description does not fit with any of the known syndromes with polymicrogyria and cytogenetic analyses including standard and high resolution chromosome analyses, telomeric FISH studies and array-CGH were normal. Consequently, the reported features in this child are unique and are likely to represent a new syndrome.
European Journal of Medical Genetics 01/2007; 50(1):48-53. DOI:10.1016/j.ejmg.2006.08.002 · 1.47 Impact Factor