Gynaecomastia has already been briefly discussed in the answer to Question 7. It can occur as a result of an hormonal imbalance, like that found in Kallmann's syndrome. The prefix gynae- means "women's" and -mastia, "the breasts". If you are a man with gynaecomastia, you have a partial, female-like enlargement of one or both breasts. Only rarely is this painful and it is generally harmless. However, it can be a source of embarrassment if you are affected.

You may remember from the answer to Question 7, that all healthy men have traces of the female hormone oestrogen as well as native testosterone in their bodies. Some testosterone is even converted to oestrogen by natural processes. There are two main causes of gynaecomastia in Kallmann's syndrome. The first cause is that due to the lack of testosterone, oestrogen has a greater influence on the body than would otherwise be the case. One of the functions of oestrogen is to encourage the growth of breast tissue and therefore gynaecomastia appears. The second reason why some male sufferers have enlarged breast tissue is due to testosterone or gonadotrophin therapy (see answers to Questions 19 & 24). Breasts may grow because the body converts too much of the injected hormone to oestrogen.

Although gynaecomastia does appear in a few cases of Kallmann's syndrome, the general belief is that it is not really any more common amongst hypogonadal sufferers than it is amongst the normal male population. Even male teenagers going through normal puberty may experience a temporary enlargement of the breasts as sometimes hormone levels take a little longer to stabilise. This is known as pseudogynaecomastia due to excess "puppy fat" and often disappears by the end of puberty. Some overweight men may also appear to have enlarged breast tissue.

If after treatment you still have gynaecomastia, you may be offered surgery by your doctor: a relatively simple operation called a subcutaneous mastectomy. This is carried out under a local or general anaesthetic and leaves only a small scar. This operation should not be confused with the type of mastectomy performed on women with breast cancer. It should also be emphasised that gynaecomastia is generally a "cosmetic" problem and is not life-threatening.

This is an uncommon characteristic estimated to affect around one-fifth of male Kallmann's syndrome patients.

The majority of people with Kallmann's syndrome with no family history of the disease, but about 40% of people have inherited the disease from one of their parents (see answer to Question 16). Bimanual synkinesis, also known as mirror movements, literally means "the simultaneous movement of both hands" and it appears to affect mainly this proportion of inherited Kallmann's syndrome sufferers.

Try this little experiment: stretch both arms in front of you, hands with the palms facing downwards. Clench a tight fist repeatedly with one hand whilst watching the other hand. If this hand makes involuntary "mirror movements" copying the hand with the clenched fist, then you have bimanual synkinesis. If your doctor asks you to try this experiment, then this is because it would be a very strong indication of whether or not you have inherited Kallmann's syndrome.

Bimanual synkinesis is often taken for granted by those who have it. If you do have it, you may have found playing the piano, swimming and climbing a ladder a little strange. This is because your arms and legs are "told" by your brain to move in the same direction at the same time.

The brain is made up of two halves, each half responsible for movement on the opposite side of the body. One theory as to why bimanual synkinesis occurs is that these two areas of the brain become "confused" and are unable to communicate with one another properly. However, the link between inherited Kallmann's syndrome and bimanual synkinesis is not yet clearly understood.

This is a common characteristic of "classic", non-inherited Kallmann's syndrome, found in both men and women with the disease. Look at Figure 14a below.

The hand is made up of 27 separate bones, five of which are called the metacarpals, one for each finger. The end of each metacarpal forms a knuckle and counting the thumb as the first finger, the fourth metacarpal is one of the bones making up part of the "ring finger". For some as yet unexplained reason, many people with Kallmann's syndrome have fourth metacarpals which are shorter than normal. The remaining fingers are relatively long, another example of the eunuchoidism discussed in the answer to Question 12.

How can you tell if you have a shortened fourth metacarpal ? Clench a tight fist with one hand. Then, take a straight object such as a pencil or ruler and lay it across the knuckles of your middle and little fingers. If you have a shortened fourth metacarpal, the knuckle of your ring finger will not touch, or will only just touch the pencil or ruler (look at Figure 14b).

Your kidneys filter your blood by extracting waste which you then expel from the body as urine. Your body can manage well with only one kidney, but should this kidney become damaged in an accident or become diseased, then the only long-term solution would be to have a kidney transplant.

It has previously been suggested that harelip and cleft palate were features of Kallmann's syndrome. These are also rare phenomena which, when they do exist in Kallmann's syndrome, usually affect those sufferers who have no family history of the disease. Harelip and cleft palate are facial deformities, both of which can usually be corrected by cosmetic surgery with good results. A harelip is a clearly visible division of the upper lip and a cleft palate is a division of the roof of the mouth. A cleft palate often appears together with a harelip. It is worth remembering that there is little evidence to suggest that harelip and cleft palate are any more common in Kallmann's syndrome sufferers than in the normal population.

Back in 1944, Franz Kallmann reported that some of his hypogonadal patients were colour blind. However, not all of his patients were anosmic and therefore would not have qualified as having Kallmann's syndrome anyway. Now, over fifty years later, it is widely believed that colour blindness is not linked to Kallmann's syndrome at all, but rather that Kallmann's original observations were coincidental.