Final answer:
Williams syndrome is a genetic disorder characterized by an elfin facial appearance, increased empathy, verbal reasoning ability, and developmental delays. It is caused by a microdeletion on chromosome 7.
Step-by-step explanation:
The diagnosis provided in the question, 'Elfin-appearance, friendly, increased empathy and verbal reasoning ability,' suggests a condition known as Williams syndrome.
Williams syndrome is a genetic disorder caused by a microdeletion on chromosome 7. This deletion affects the structure and function of certain genes, leading to the characteristic features and traits associated with Williams syndrome.
Some of the main features of Williams syndrome include an 'elfin' facial appearance, friendly and outgoing personality, increased empathy and verbal reasoning ability, as well as developmental delays in various areas such as motor skills and cognitive abilities.