The report shows that the child has a deletion of about 4.5 megabases (Mb) on the short arm of chromosome 18 (18p). This means that a segment of DNA is missing from one copy of chromosome 18. The deletion involves 11 genes, which are named in the report.

Chromosome 18p deletion syndrome is a rare genetic disorder that can affect various aspects of physical and mental development, such as growth, intelligence, speech, facial features, and behavior. However, the symptoms and their severity can differ a lot among people with this disorder depending on how big and where the deletion is.

The report states that the child’s deletion is smaller than most of the cases of chromosome 18p deletion syndrome that have been reported before, and that some of the genes that are deleted are not well understood. This means that it is hard to tell how this deletion impacts the child’s health and development, or how it is related to his ASD diagnosis.