Final answer:
Down syndrome is caused by having three copies of chromosome 21, a condition known as trisomy 21. Klinefelter's syndrome shares a similarity with Down syndrome in that it also results from a chromosomal abnormality—specifically, the presence of an extra X chromosome, resulting in an XXY karyotype.
Step-by-step explanation:
Down Syndrome and Associated Disorders
Down syndrome is characterized by an abnormality in chromosome 21, where three copies are present instead of the usual two, a state known as trisomy 21. Individuals with Down syndrome may experience intellectual disability, congenital heart disease, and have distinct facial features. Similar to Down syndrome, Klinefelter's syndrome is also a chromosomal disorder but it involves an extra X chromosome leading to an XXY karyotype.
Unlike conditions such as Huntington's disease, Alzheimer's disease, and Parkinson's disease, which are associated with gene mutations or neurodegenerative processes, both Down syndrome and Klinefelter's syndrome derive from an atypical chromosome count. Therefore, out of the options provided, Klinefelter's syndrome is the disorder that also involves a chromosomal defect similar to that of Down syndrome.
Turner's syndrome, another chromosomal condition, is characterized by having a single X chromosome (monosomy) and affects only females, leading to different manifestations such as sterility. Hence, the disorder that shares a characteristic of chromosomal abnormality with Down syndrome is Option B. Klinefelter's syndrome.