Eulalee Thompson - BE WELL

It is generally believed that the embryo by default is female. Females carry two X chromosomes (XX) among the 23 pairs of chromosomes in each cell. In about the seventh week, the embryonic presence of the Y chromosome (XY) provides instructions for the development of male characteristics. The hormone, testosterone is produced and the structures become male.

However, as Dr Leslie Gabay, Kingston-based paediatric endocrinologist, points out, many things can go wrong in the change process.

"On the Y chromosome, there is a code that converts the primitive gonad to testicles. The testicles then produce testosterone then change (the embryo) to male," he said. "(But) we could have XY but don't get the code across so stay female ... or hormones are like keys that (have to) fit in a lock so that we can get the effect of the hormones. So we could have normal testicles, testosterone but don't have the lock to fit in, so don't get the conversion to male. This is called androgen insensitivity syndrome," he added.

The literature points to many chromosomal conditions of the sex chromosomes that affect sex deter-mination (that is the display of sexual characteristics of male or female), sexual development and fertility. Some of the conditions are mild, others severe and can be associated with either structural changes in the chromosomes, missing a copy of the chromosome, or having extra copies.

Sex verification tests

This topic of what makes us male or female would be an ongoing interest of genetic scientists, but has become an issue of public discussion after the International Association of Athletics Federation (IAAF) announced that South African Caster Semenya, the 800m women world champion, was undergoing sex-verification tests. The athlete looks male but, in various published interviews, her father and other relatives indicate that she is in fact female and considers herself female.

"What makes us male or female? That is like saying, 'Who is God?' Or, 'Who am I?' As I say to people, you have to look at what the purpose of your sex is. If the purpose of chromosomes is to transfer genetic material from one generation to the next, then you will take a particular perspective," Gabay opines.

He believes that at the end of the day, socially, it is one's body type (how we look) and genitals which are important in determining sex. A recent issue of The New Scientist reports the case of a unnamed seven-year-old girl with a Y chromosome, accidentally discovered when she was genetically tested before birth. The report indicates that the child "doesn't have ambiguous gonads, shrivelled testes or other developmental defects. She instead has a normal vagina, cervix and set of ovaries". A team led by Anna Biason-Lauber of University Children's Hospital in Zurich, Switzerland, thinks the patient's normalcy is due to mutations in a poorly understood gene on chromosome 17 called CBX2.

Sex vs gender

Any good student of sociology knows that sex, the biological designation of male or female characteristics, is different from gender, a social construct ascribing roles, behaviour and relations between men and women. Gabay believes that superimposing the issue of gender on sex further complicates the question of what makes us male or female.

"We now have gender, and that is how we see ourselves. I may be in a male body but my psychology is female and how I see myself is female. And a lot of people will want to make the link between this topic and homosexuality, but it is not the same thing," he said.

Jamaica has its fair share of unclear sex-identification issues. Gabay indicates that between four to six cases of ambiguous genitalia (which is where the clinician is unable to clearly define the sex of the child) are identified here each year. The diagnosis of androgen insensitivity syndrome is less common and is only seen about once every five years.

Eulalee Thompson is health editor and a professional counsellor. Email: eulalee.thompson@gleanerjm.com.