Final answer:
Angelman syndrome is typically not observed with a family history since most cases are sporadic, caused by deletions or mutations that occur randomly. However, in rare instances, inherited genetic changes can pose a risk for the condition.
Step-by-step explanation:
It is generally false that there is a typical family history of Angelman syndrome. Angelman syndrome is usually caused by a deletion or mutation in the maternal copy of the UBE3A gene on chromosome 15. Most cases of Angelman syndrome are not inherited, occurring as random events during the formation of reproductive cells or in early embryonic development. However, in a small percentage of cases, a person can inherit a mutated gene from a parent who has a genetic change called a uniparental disomy, where two copies of a chromosome or part of a chromosome come from one parent and no copies from the other parent.
Since the condition often occurs sporadically without a family history, genetic counseling can help assess the risk in future pregnancies if someone has a child with Angelman syndrome. Genome sequencing or chromosomal analysis may reveal whether there is a risk of recurrence in such cases.