Gynaecomastia refers to

1. Masculine development in females

2. Development of breasts in males

3. Development of female characters in male

4. Reduced breasts in the female

All are X-linked traits, except

1.  Colourblindness

2.  Haemophilia

3.  Deficiency of glucose-6-phosphate dehydrogenase

4.  Hypertrichosis