Klinefelter syndrome is a condition that affects males because of irregularities in the chromosomes. It is named after Dr Henry Klinefelter, who first described it in 1942 CE.
1. Sterility, as a result of the lack of cells that produce sperm.
2. Larger breasts.
3. Weak muscles, like those of a woman.
4. Pubic hair may resemble that of the female.
5. Impotence and low sex drive.
6. Small testicles.
Individuals who are affected by this condition are males, and the rulings concerning males – particularly with regard to interactions with women – also apply to them; so it is haraam for them to mix with women, look at them, imitate them and other rulings governing interactions of men with women.
They may seek treatment for this disease, and there is no sin on them and no shar ‘i blame for having physical features that resemble those of females. But they also have to avoid resembling women in their tone of voice, movements, clothing and so on, because for men to imitate or resemble women is a major sin, as we have explained in fatwa no. 81994
With regard to hijab, he does not have to wear hijab, because he is a man and hijab is only for women, not men. But we should point out an important matter, which is that if he is afraid in a particular situation that he may be a source of temptation for people, then he must avoid that situation. The same applies to anyone who fears that he may be tempted if he mixes with a person who has this condition; he should avoid interacting with him and he should lower his gaze and avoid looking at him, especially if that person is good-looking. In that case he comes under the same ruling as the ruling on “beardless youths,” in whose case there may be the fear of temptation.
And Allah knows best.