You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Intragenic deletions of the IGF1 receptor gene in five individuals with psychiatric phenotypes and developmental delay. Haploinsufficiency of the gene encoding the insulin-like growth factor 1 receptor (IGF1R), either caused by telomeric 15q26 deletions, or by heterozygous point mutations in IGF1R, segregate with short stature and various other phenotypes, including microcephaly and dysmorphic facial features. Psychomotor retardation and behavioral anomalies have been seen in some cases. Here we report small, intragenic deletions of IGF1R, identified by chromosome microarray analysis in two unrelated families affected primarily with neuropsychiatric phenotypes including developmental delay, intellectual disability and aggressive/autoaggressive behaviors. The deletions are in frame, and both wild-type and mutant mRNAs are expressed as measured by quantitative real-time PCR. While short stature is considered a phenotypic hallmark of IGF1R haploinsufficiency, the present report suggests that in frame exon deletions of IGF1R present predominantly with cognitive and neuropsychiatric phenotypes.European Journal of Human Genetics advance online publication, 13 March 2013; doi:10.1038/ejhg.2013.42.
{"Chemical": []}