Question

Which list contains only Mendelian disorders?

Options

• Haemophilia, Turner's syndrome, Sickle-cell anaemia, Klinefelter's syndrome

• Down's syndrome, Thalassaemia, Colour blindness, PKU

• Haemophilia, Thalassaemia, Sickle-cell anaemia, Colour blindness, PKU

• Down's syndrome, Turner's syndrome, Klinefelter's syndrome, Haemophilia

Answer 1

Haemophilia, thalassaemia, sickle-cell anaemia, colour blindness, and phenylketonuria (PKU) are all Mendelian disorders caused by single-gene mutations. Turner's syndrome and Klinefelter's syndrome are chromosomal disorders.