One of your brother's friends, dylan, is unusually short with a stocky build; has a flat face, a large tongue, and an extra fold of skin on his eyelids; and suffers from cognitive deficits, hearing impairments, and a heart defect. dylan likely has

Dylan likely has Down Syndrome /  21 Trisomy Syndrome.

Explanation:

Down Syndrome is a genetic disorder in which the person has an extra copy of chromosome 21, this is why the disorder is known as Trisomy 21.  This extra copy changes how the body and the brain develope, which can cause mental and physical problems.

Children with this disorder usually have a low intellectual level, the most frequent cause of identifying mental delay of genetic origin.

Some of the characteristics of these children are slight diminution in the skull size, almond-shaped eyes, a short neck, small ears, a small mouth, a large tongue tends to get out of the mouth, narrow auditive conduct, tiny hands, and feet, weak muscular tone, and they are usually short in height.

There are also some medical problems such as hearing loss, apnea, ear infections, ocular problems, heart defects, intestinal malformations, hypothyroidism, hip dislocation, anemia, among others.

i was thinking 4.0 v hope this