How does Angelman's syndrome trigger laughter?

[Pyrus]

We all know that do to microdeletion of maternal chromosome 15, Angelman syndrome occurs. But what is the reason that people with this syndrome trigger sudden laughter for long time.
This means that there is genetic relation between laughter and genes on 15th chromosome.

 

[jim mcnamara]

Deletion are removals of DNA or damage to part of the DNA of the gene. So consider that the deletions remove genes whose expression involves laughing under defined conditions, rather than any old time.
Sort of backwards from your perception.

Cause: The "loss" of gene UBE3A is responsible largely because of genomic imprinting - expression of ONLY the mother's UBE3A. If it has problems then the child has no UBE3A expression in some brain tissue. The male parent's UBE3A is not activated. And Angleman's patients display all kinds of physical and behavioral abnormalities, and cognitive deficits. Not just laughter. The Angleman person's brain is "defective" to a larger or smaller degree.

https://rarediseases.info.nih.gov/diseases/5810/angelman-syndrome

Note: There are dozens follow-on links to relevant pages from there

 

[Fervent Freyja]

What? No, correlation is not causation. I haven't read where laughter is related to any particular gene. That is a characteristic of this genetic syndrome, when combined it all indicates that it causes a neurodevelopmental disorder, which involves a host of characteristics. My baby brother has a mutation on chromosome 5, that does not mean a gene for the numerous characteristics specific to his syndrome or that he shares with other genetic syndromes can be found there, just the mutation.