Gene Determination - Essay Example

Gene Determination Q1. Birth defect of the sex organs (Genital Birth Defects) that result in a problem with assigning a definite sex to a newborn child is known as Ambiguous Genitalia or Atypical Genitalia (Committee on Genetics, 2000, Birth Defects, 2005). This condition is said to occur in about one in every 3,000 live births and is characterized by the presence of either a combination of male and female external genitalia or an external genitalia that cannot be clearly assigned to a gender (Birth Defects, 2005). To properly understand the occurrence and causes of this condition, a clear understanding of the normal genetic and hormonal influences that interplay in genital formation and development is important (Committee on Genetics, 2000). Basically, the sex of a child is determined at conception. The mother, through the ovum, provides the X chromosome, while the father's sperm, the main determinant of the baby's sex, carries either an X chromosome or a Y chromosome. An XX embryo is a female, while an XY embryo is a male. Before the 6th week (or 8th week according to Committee on Genetics, 2000), the embryo develops undifferentiated gonadal tissues and also have primordial structures that are capable of developing into both male and female genitalia (Committee on Genetics, 2000, Birth Defects, 2005). The process of sexual determination and thus the genital appearance of the baby at birth are largely determined by the presence or absence of genetic and hormonal influences responsible for the process of male differentiation. The gene SRY on the short arm of the Y chromosome has been described as the major player in this process (Committee on Genetics, 2000). Under the influence of this gene, the undifferentiated gonad forms the testes, while the internal genital parts transform into the prostate gland and vas deferens. The male hormones produced by the testes allow the penis and scrotum to develop. However, in the absence of this influence, the female sexual differentiation occurs. The gonads turn into ovaries which start producing female sex hormones while the internal genital parts transform into the uterus, fallopian tubes and vagina (Committee on Genetics, 2000; Birth Defects, 2005). Thus "for normal genital development, the gender 'message' must be communicated from the sex chromosomes to the gonads. The gonads must then manufacture appropriate hormones and the genital tissues and structures have to respond to these hormones. Any deviations along the way can cause ambiguous genitalia" (Birth Defects, 2005). Some of the more specific causes of atypical genitalia that have been highlighted include: Androgen Insensitivity: This is a genetic defect. It is characterized by the fetal tissues insensitivity to male androgen hormones. In this case, the baby could be a male but develops female genitalia due to the gonads insensitivity to the influences and control of the male hormone. For example, a newborn may have some of the female reproductive organs but also have testicles. Congenital adrenal hyperplasia (CAH) - an inherited condition that affects hormone production. A child with CAH lacks particular enzymes, and this deficiency triggers the excessive manufacture of male hormones. In this case, a female may be born with what appears to be male genitalia due to the excessive male hormones. Sex Chromosome anomaly: Instead of the normal XX or XY chromosomal combination, an embryo may have a mixture of both or the misplacement of some genes in one of the chromosomes. A particular example of this is the gene known as WNT-4 on chromosome 1. It has been established that second copy of this gene could result in problems with sexual differentiation of a baby (UCLA geneticists, 2001; Committee on Genetics, 2000; Birth Defects, 2005). Q2. It could be possible that Dawn Simmons conceived and had a child. A reasonable explanation for this would be that, Dawn Simmons was actually a female at birth that suffered Congenital Adrenal Hyperplasia (CAH). As explained above, this condition, during embryonic development, is characterized a by a deficiency of several important hormones, which then triggers the production of excessive amounts of male hormones. The presence of the large concentration of male hormones possibly masculinized her external genitalia and made her appear like a male at birth instead of the female that she is. Although, another contention here is whether ambiguous genitalia can cause infertility and problems with sexual functioning, in this regard, one may conveniently assume that, perhaps, the degree of masculinization that occurred during development, due to this anomaly, is not enough to affect her internal genital organs severely. According to Committee on Genetics (2000), "all female infants virilized because of CAH or maternal androgens are potentially fertile and should therefore be raised as girls" (p.141). In addition, the sex change could be seen to have corrected the external genitalia, creating a concordance with her internal genitalia and thus enabling proper sexual functioning and thus the ability to conceive and carry a baby to full term. Q3. It should be legally possible to, in any state, to have ones birth certificate changed to reflect sex reassignment. Being able to obtain correct identity documentation is the key to equal participation in employment and educational opportunities for a transsexual person. With the contemporary understanding that transsexualism (changing from one sex to the other) is a legitimate medical condition and that sex reassignment is the only effective treatment, refusing to legally recognize a transsexual person could be seen to be cruel and senseless. It serves no useful purpose, from a practical point of view, while at the same time inflicts grievous psychological, social and emotional stress on the person (Birth Certificate Sex Designation, 2003). From a practical point of view, refusing a transsexual person legal recognition exposes the person to the constant threat of exposure and invasion of privacy, frequently prevents the person from obtaining employment or advancing in their career, and creates innumerable other problems ranging from the inability to travel safely outside the country to the inability to purchase health or life insurance in the person's reassigned gender. When observed from a psychological perspective, the impact of refusing a transsexual person legal recognition could even be more devastating. It may effectively negate the therapeutic benefits of undergoing sex-reassignment, resulting in profound depression and dysfunction (Birth Certificate Sex Designation, 2003). Almost all states permit transsexual persons to be legally recognized and issued with a birth certificate reflecting the new gender, either through statute or by administrative policy. The three states that are known to refuse such legal recognition of transsexual persons are Idaho, Ohio, and Tennessee. However, New York City is described as the only jurisdiction in the country that issues new birth certificate to some transsexual persons with the gender designation left blank (Birth Certificate Sex Designation, 2003). Q4 It would be virtually impossible for a genetic (chromosomal) male to conceive and give birth to a baby due to a sex change operation. The aim of sex change or Sexual Reassignment Surgery (SRS) as it is called, is in most cases, to modify the external genitalia and features of the transsexual person and to make it appear as close to the desired sex as possible. However, internal physiology is an entirely different issue. There is hardly any medical operation or procedure that can successfully convert an XY male to a XX female. Also, the absence of the actual sex glands (ovaries and testes) in these transsexuals make reproduction completely out of reach. For instance, a male undergoing sexual change to female could be made to develop breasts through breast augmentation and also speak like a female through other feminizing surgeries, but he could not be made to develop or possess ovaries which are vital for reproduction. Sexual Reassignment Surgery attempts to change the anatomy and function of the genitalia in a way that it could appear and function like that of the desired sex. Thus, the several surgical procedures that are carried out are aimed at converting or replacing a gender's genitals with the other. For a male to female sexual change, some of these operations include: Augmentation Mammaplasty (breast augmentation): creating breasts for the male undergoing sex change to female Vaginoplasty: Removing the penis and replacing it with what could serve as a vagina. Depending on the preference of the person, the vagina can be made to be penetrable or not. According to Bowman and Joshua (2006) the aim of Vaginoplasty includes: creation of a sensate and aesthetically acceptable vulva (including clitoris, labia minora and majora, and vaginal introitus) shortening of the urethra, with creation of a urethral opening that allows a downward urinary stream creation of a stable and sensate neovagina with adequate dimensions for penetrative sexual intercourse, ideally lined with moist, elastic, hairless epithelium elimination of erectile tissue (to avoid narrowing of the introitus and protrusion of the urethral meatus/clitoris during sexual arousal) preservation of orgasmic capability (p.6) Facial feminizing surgery: This surgical procedure attempts to reduce stereotypically masculine features and impart more conventionally feminine features to the person's head and neck region, making such a person appear more feminine. Voice pitch-elevating surgery: involves surgical alteration of the laryngeal framework and/or vocal cords to modify voice from masculine to feminine, especially where speech therapy alone has not achieved the desired effect. Q5 The story in the paper is possibly correct since we now know that Congenital adrenal hyperplasia (CAH) an adrenal abnormality could make a female genitalia appear male at birth. Also, since, it is clear that such genital birth defects do not affect fertility in most cases, the fact that Dawn Simmons had a baby successfully could further add credibility to the story, considering the fact, again, that sexual change is not compatible with fertility. If an adrenal abnormality like CAH caused her female genitalia to appear male, sex change could be a treatment option, though there are several less invasive treatment options. But depending on the severity of the abnormality, sex change could be a good choice. However, such sex change would not be similar to what obtains when a genetic male wishes to change to a female. The surgery carried out to treat this genital birth defect is mostly a reconstructive surgery, a form of cosmetic surgery to make the genitals look more natural. Depending on the severity of the condition, this could range from uncovering the vagina hidden on the skin to removing excess masculine tissues around the clitoris that makes appear like a penis (Ambiguous genitalia, 2006). Other treatment options may include hormonal therapy to correct the underlying hormonal imbalance, if this is responsible for the condition; however, surgery is still required to modify the external genitalia. References Ambiguous genitalia; An Overview (2006). Diseases and Conditions; CNN.com. Available online at < http://www.cnn.com/HEALTH/library/DS/00668.html> Birth Certificate Sex Designation: An Overview of the Issues [Online Essay]. Retrieved Online 17th April 2006 from Birth Defects - Ambiguous Genitalia (online). Better Health Channel. Retrieved 17th April 2006 from Bowman and Joshua (2006). Care of the Patient Undergoing Sex Reassignment Surgery (SRS). Vancouver Coastal Health, Transcend Transgender Support & Education Society, and the Canadian Rainbow Health Coalition. Available online at Committee on Genetics (2000). Evaluation of the Newborn With Developmental Anomalies of the External Genitalia. American Academy of Pediatrics. Pediatrics Vol. 106 No. 1 pp. 138-142 UCLA geneticists identify cause of malformed genitalia; finding will improve sex assignments in ambiguous newborns (2001). EurekAlert University of California - Los Angeles. Retrieved Online 17th April 2006 from < http://www.eurekalert.org/pub_releases/2001-04/UNKN-Ugic-3004101.php > Read More