Mrs. V, a healthy 45-year-old woman, gives birth to a child. There...

Mrs. V, a healthy 45-year-old woman, gives birth to a child. There are no outward complications associated with the birth but, when examined by the pediatrician, the child exhibits abnormal facies, a single palmar crease, hypotonic muscles, and loose pelvic joints. Following chromosomal analysis, a diagnosis of Down syndrome is made.