Sex identification in sports

SEX TESTING IN SPORTS

Sex testing is a process of verifying athlete sex to determine eligibility to participate in a particular competition.

By definition, SEX refers to the biological and physiological characteristics which delineates a male from a female. These encompass genetic, gonadal, hormonal and phenotypic make up of an individual.

GENDER on the other hand, refers to a social construct based on activity, behavior and attributes which are given by society to identify one as either male or female. Of late, various gender identities have emerged hence the identity of ‘ other’ in the gender options in some settings.

The traditional definition of SEX has been sexual anatomy. The contextual definition of genetic makeup has resulted in presence of ambiguity in sexual makeup i. e. a male genetic makeup ( genotype) on a female structural makeup ( phenotype) or vise versa. These are termed differences in sexual development ( DSD).

Lack of understanding on the science behind this has led to controversies, stigma and certain ‘ tags’ on involved individuals such as in the Castor Semenya ( RSA) or Santhi Soundarajan ( India) cases.

BASIC SEXUAL DEVELOPMENT CONCEPTS

A sperm and ovum form a zygote during fertilization. The resultant genotype ( genetic make-- up) is either female ( XX) or male ( XY). The default pathway results in development of a female ( XX) through formation of ovaries and subsequent female related hormones ( estrogen and progesterone).

The presence of an SRY ( sex region of Y) gene leads to a male pathway ( XY). This entails subsequent development of testes which then produce testosterone from the leydig cells. Absence of an SRY gene results in development of a female ( XX).

The testosterone is further converted to a more active form of dihydrotestosterone by a 5- alpha- reductase enzyme. This process requires normal androgen receptor sensitivity.

From this process, the normal outcome is a set of 46 chromosomes in each human cell like in females 46XX or 46XY in males ( A euploid or normal set of chromosomes). Masculinization ( normal sexual development before birth) is then followed by Virilization ( normal sexual development at puberty) during growth.

NB: Testosterone isn’t exclusive to males only. Considerable levels exist in females and as such these relative levels provide a reference point in relation to sporting participation.

VARIANTS IN DEVELOPMENT

Variations that may exist from the normal male/ female development can affect the: Chromosomal abnormality: ( abnormal number e. g. 45X or mosaic pattern in genetic expression across cells) during cell division; or

Gene translocations: where 2 chromosomes exchange genetic material it may affect their physical appearance. e. g. when a gene translocation involves the SRY gene one may have a male genotype ( XY) with a female phenotype ( physical appearance).

Androgen receptor sensitivity: Sensitivity may be partially absent ( Partial androgen insensitivity syndrome, PAIS) or completely absent ( complete androgen insensitivity syndrome, CAIS). These

persons tend to have hyperandrogenism reflected by high testosterone levels. Other causes that need to be ruled out include adrenal hyperplasia, polycystic ovarian syndrome or tumors.

SEX TESTING in sports is designed to pick these variations that may result in hyperandrogenism. No single sex test identifies one exclusively as being male or female hence a full medical evaluation is needed to reach a consensus.

SEX DETERMINATION TESTING

The first documented form of sex testing was in the 1936 Berlin Olympics by visual inspection. Routine testing was abandoned in 1999 prior to the Sydney 2000 Olympic games however it could still be conducted in individual cases. It was since re- introduced post the Castor Semenya case. The complement of tests include:

1. Physical examination – Not sorely reliable, doesn’t cover the genotype

2. Chromosomal testing ( identifies if XX ( female) or XY ( male)). Uses a Barr body test via buccalswab – a positive test outlines one as female ( XX) and vise versa. Not sorely reliable due to different karyotypes e. g. 47XXY.

3. DNA testing: uses PCR to amplify DNA to pick out the SRY gene. Not sorely reliable due to the possibility of mutated, missing or translocated SRY gene).

4. Testosterone level testing: Recently adopted by the IAAF, IOC based on evidence that high levels offer an unfair advantage. The normal female range is 0.06 to 1.68 nmol/ L. A level of > 10nmol/ Lexcludes a female from participating in female sports ( IAAF 2011). Females with features of hyperandrogenism or Difference in sexual development ( DSD) need to obtain levels