<s>[INST] My son has the factor xii missing in his blood, all the health professionals we ve spoken too say it s not a problem, however my son does suffer badly with constant exhaustion and irritability. He also has a sleep disorder (undiagnosed) which makes him need a lot more sleep than average (around 10 - 12). My son was considerably premature at birth and under weight but has been relatively normal in size since he was 5 years old, he is now 31, average hight and weight. Could the missing clotting factor play a part in his condition or it this just co-incidental? [/INST] Hi, Factor 12 deficiency has no correlation with exhaustion and irritability. Factor 12 deficiency is totally asymptomatic and also it doesn't lead to bleeding. I can assure you about this. I hope this has helped you. If you do not have any clarification, you can close the discussion and rate the answer. Wish you good health. Regards :Dr Deepak Patel </s>