How many of the following diseases can be studied with the help of pedigree chart?

Turner's syndrome, Phenylketonuria, Down's syndrome, Sickle-cell anemia, Klinefelter's syndrome, Haemophilia, Cystic fibrosis, Myotonic dystrophy

The correct option is C Five

The pedigree chart is a method of study of the human genetic disorder. The pattern of inheritance such Mendelian disorders can be traced in a family by the pedigree chart. Mendelian disorders are phenylketonuria, sickle-cell anemia, hemophilia, cystic fibrosis, and myotonic dystrophy.

Rest turner's syndrome, Down's syndrome, and Klinefelter's syndrome is chromosomal disorders and cannot be studied by a pedigree chart.

So, the correct option is C.